Self-powered switch initiation system

ABSTRACT

A self-powered switching system using electromechanical generators generates power for activation of a latching relay. The electromechanical generators comprise electroactive elements or magnetic based microgenerators that may be mechanically actuated to generate electrical power. The associated signal generation circuitry may be coupled to a transmitter or transceiver for sending and/or receiving RF signals to/from a receiver which actuates the latching relay. Power may be stored within the circuit using rechargeable batteries for powering or supplementing power to the transmitter or transceiver.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to switching devices forenergizing lights, appliances and the like. More particularly, thepresent invention relates to a self-powered switch initiator device togenerate an activation signal for a latching relay. The power isgenerated through an electroactive element and is sent through signalgeneration circuitry coupled to a transmitter for sending one or moreunique and/or coded RF signals to one or more receivers that actuate thelatching relay. The receivers have the ability to store a plurality ofcodes in order to respond to multiple transmitters and multipletransmitter functions. The invention also includes the use of one ormore transceivers that are powered by the electroactive generators or bythe generators in conjunction with rechargeable batteries for providingsupplemental power to the RF transmitter circuit and/or transceivers.

2. Description of the Prior Art

Switches and latching relays for energizing lights, appliances and thelike are well known in the prior art. Typical light switches comprise,for example, single-pole switches and three-way switches. A single-poleswitch has two terminals that are hot leads for an incoming line (powersource) and an outgoing line to the light. Three-way switches cancontrol one light from two different places. Each three-way switch hasthree terminals: the common terminal and two traveler terminals. Atypical pair of three-way switches uses two boxes each having two cableswith the first box having an incoming line from a power source and anoutbound line to the second box, and the second box having the incomingline from the first box and an outbound line to the light.

In each of these switching schemes it is often necessary to drill holesand mount switches and junction boxes for the outlets as well as to runcable. Drilling holes and mounting switches and junction boxes can bedifficult and time consuming. Also, running electrical cable requiresstarting at a fixture, pulling cable through holes in the framing toeach fixture in the circuit, and continuing all the way back to theservice panel. Though simple in theory, getting cable to cooperate canbe difficult and time consuming. Cable often kinks, tangles or bindswhile pulling, and needs to be straightened out somewhere along the run.

Remotely actuated switches/relays are also known in the art. Knownremote actuation controllers include tabletop controllers, wirelessremotes, timers, motion detectors, voice activated controllers, andcomputers and related software. For example, remote actuation means mayinclude receiver modules that are plugged into a wall outlet and intowhich a power cord for a device may be plugged. The device can then beturned on and off by a remote controller/transmitter. Other remoteactuation means include screw-in lamp receiver modules wherein thereceiver module is screwed into a light socket, and then a bulb screwedinto the receiver module. The light can be turned on and off and can bedimmed or brightened by a remote controller/transmitter.

Another example of one type of remote controller for the above describedmodules is a radio frequency (RF) base transceiver. With thesecontrollers, a transceiver base is plugged into an outlet and cancontrol groups of receiver modules in conjunction with a hand heldwireless RF remote. RF repeaters may be used to boost the range ofcompatible wireless remote transmitters, switches and security systemsensors by up to 150 ft. per repeater. The transceiver base is requiredfor these wireless RF remote control systems and allows control ofseveral lamps or appliances. Batteries are also required in the handheld wireless remote control systems.

Rather than using a hand held RF remote transmitter, remote walltransmitters may be used. These wall transmitters, which are up to ¾″thick, are affixed to a desired location with an adhesive or fastener.In conjunction with a transceiver base unit (plugged into a 110Vreceptacle) the remote wall transmitter may control compatiblereceiver/transceiver modules and their associated switches. The wirelesstransmitters send an RF signal to the transceiver base unit and thetransceiver base unit then transmits a signal along the existing 110Vwiring in the home to compatible switches or receiver modules. Eachswitch can be programmed with an addressable signal. Wirelesstransmitters also require batteries.

These remotes control devices may also control, for example, audio/videodevices such as the TV, VCR, and stereo system, as well as lights andother devices using an RF to infrared (IR) base. The RF remote cancontrol audio/video devices by sending proprietary RF commands to aconverter that translates the commands to IR. IR commands are then sentto the audio/video equipment. The infrared (IR) base responds toinfrared signals from the infrared remotes and then transmits equivalentcommands to compatible receivers.

A problem with conventional wall switches is that extensive wiring mustbe run both from the switch boxes to the lights and from the switchboxes to the power source in the service panels.

Another problem with conventional wall switches is that additionalwiring must be run for lights controlled by more than one switch.

Another problem with conventional wall switches is that the voltagelines are present as an input to and an output from the switch.

Another problem with conventional wall switches is the cost associatedwith initial installation of wire to, from and between switches.

Another problem with conventional wall switches is the cost andinconvenience associated with remodeling, relocating or rewiringexisting switches.

A problem with conventional RF transmitters is that they require anexternal power source such as high voltage AC power or batteries.

Another problem with conventional battery-powered RF transmitters is thecost and inconvenience associated with replacement of batteries.

Another problem with conventional AC-powered RF transmitters is thedifficulty when remodeling in rewiring or relocating a wall transmitter.

Another problem with conventional RF switching systems is that a paircomprising a transmitter and receiver must generally be purchasedtogether.

Another problem with conventional RF switching systems is thattransmitters may inadvertently activate incorrect receivers.

Another problem with conventional RF switching systems is that receiversmay accept an activation signal from only one transmitter.

Another problem with conventional RF switching systems is thattransmitters may activate only one receiver.

Another problem with conventional RF switching systems is thattransmitters may be able to transmit only one signal.

Another problem with conventional RF switching systems is thattransmitters may not have multiple activation signals, and that thesignals are not selectable from the transmitter.

Another problem with conventional RF switching systems is thattransmitters and receivers may not exchange feedback information toindicate completion of the desired action at the receiver.

Another problem with conventional RF switching systems is that there isno display to indicate completion of the desired action at the receiver.

Accordingly, it would be desirable to provide a network of switchinitiators and/or latching relay devices that overcomes theaforementioned problems of the prior art.

SUMMARY OF THE INVENTION

The present invention provides a self-powered switching initiator orlatching relay device using an electroactive generator or transducer.The electroactive element in the generator is capable of deforming witha high amount of bending displacement, and when deformed by a mechanicalimpulse generates an electric field. The electroactive transducer isused as an electromechanical converter/generator for generating anelectrical signal that, with the accompanying circuitry, generates an RFsignal that initiates a latching or relay mechanism. The latching orrelay mechanism thereby turns electrical devices such as lights andappliances on and off or provides an intermediate or dimming signal, orinitiates other functions.

The mechanical actuating means for the electroactive generator elementapplies a suitable mechanical impulse to the electroactive generatorelement in order to generate an electrical signal, such as a pulse,multiple pulses and/or waves having sufficient magnitude and duration topower and actuate downstream circuit components. A mechanism similar toa light switch, for example, may apply pressure through a toggle, snapaction, paddle, plunger, plucking or ratchet mechanism. Larger ormultiple electroactive generator elements may also be used to generatethe electrical signal. Co-owned U.S. Pat. No. 6,630,894 entitled“Self-Powered Switching Device,” which is hereby incorporated byreference, discloses a self-powered switch where the electroactiveelement generates an electrical pulse. Copending application Ser. No.09/990,617 entitled “Self-Powered Trainable Switching Network,” which ishereby incorporated by reference, discloses a network of switches suchas that disclosed in U.S. Pat. No. 6,630,894, with the modification thatthe switches and receivers are capable accepting a multiplicity of codedRF signals. Copending application Ser. No. 10/188,633 entitled“Self-Powered Switch Initiation System,” which is hereby incorporated byreference, discloses a network of switches such as that disclosed inU.S. Pat. No. 6,630,894, with additional modifications to the coded RFsignals, multiple training topologies, and an improved mounting andactuation means, as well as circuitry to support the output electricalsignal of the transducer.

In the present invention, modifications have been developed to theelectroactive element, its mounting and its mechanical actuator,resulting in a modification in the character of the electrical signalproduced by the transducer, as well as modifications to the electricalcircuitry. The present invention describes a self-powered switchinitiation system having an electroactive element and accompanyingcircuitry designed to work with an oscillating electrical signal. Toharness the power generated by the electroactive element, theaccompanying RF signal generation circuitry has also been modified touse the electrical signal most efficiently. Additionally, the use ofrechargeable batteries may improve the usefulness, life and efficiencyof the circuit, as well as providing supplemental power for use in areceiver, transceiver or display. Furthermore, the system may beenhanced by another power source such as a solar/light powered storageand supplementation device, such as the high efficiency light powereddisplays used in calculators, or by pressure and/or temperaturesensitive devices for generation of supplemental power.

In one embodiment of the invention, the electroactive generator outputsignal powers an RF transmitter which sends an RF signal to an RFreceiver which then actuates the relay. In yet another embodiment, theelectromagnetic or electroactive generator output signal powers atransmitter, which sends a pulsed (coded) RF signal to an RF receiverwhich then actuates the relay. Digitized RF signals may be coded (aswith a garage door opener) to only activate the relay that is coded withthat digitized RF signal. The transmitters may be capable of developingone or more coded RF signals and the receivers likewise may be capableof receiving one or more coded RF signal. Furthermore, the transmittersmay be capable of transmitting a plurality of coded signals which areselectable, using for example a selector switch, dial or scaled slidingmechanism. Furthermore, the receivers may be “trainable” to accept codedRF signals from new or multiple transmitters. In another embodiment ofthe invention, rechargeable batteries are used to capture some of theelectrical output of the generator and apply the stored energy tocircuit components. Lastly, another embodiment of the invention uses atransceiver in conjunction with the battery and transmission circuit tosend and receive RF signals within the system, for example where afeedback or confirmation signal is sent from the receiver-transceiver tothe transmitter-transceiver to acknowledge receipt or completion of thetransmitted command function.

Accordingly, it is a primary object of the present invention to providea switching system in which an electroactive or piezoelectric element isused to power an RF transmitter for activating an electrical device.

It is another object of the present invention to provide a device of thecharacter described in which transmitters may be installed withoutnecessitating additional wiring.

It is another object of the present invention to provide a device of thecharacter described in which transmitters may be installed withoutcutting holes into the building structure.

It is another object of the present invention to provide a device of thecharacter described in which transmitters do not require externalelectrical input such as 120 or 220 VAC or batteries.

It is another object of the present invention to provide a device of thecharacter described incorporating an electroactive converter thatgenerates an electrical signal of sufficient duration and magnitude toactivate a radio frequency transmitter for activating a latching relayand/or switch initiator.

It is another object of the present invention to provide a device of thecharacter described incorporating a transmitter that is capable ofdeveloping at least one coded RF signal.

It is another object of the present invention to provide a device of thecharacter described incorporating a receiver capable of receiving atleast one coded RF signal from at least one transmitter.

It is another object of the present invention to provide a device of thecharacter described incorporating a receiver capable of “learning” toaccept coded RF signals from one or more transmitters.

It is another object of the present invention to provide a device of thecharacter described for use in actuating, operating or altering thestate of lighting, appliances, controls, and security devices and otherelectrical and electromechanical fixtures in a building.

It is another object of the present invention to provide a device of thecharacter described incorporating storage means for electrical energygenerated at the transmitter.

It is another object of the present invention to provide a device of thecharacter described incorporating a receiver and transmitter or atransceiver for closed loop operation and system feedback.

It is another object of the present invention to provide a device of thecharacter described incorporating controller on the transmitter forselecting from a variety of transmissible codes.

It is another object of the present invention to provide a device of thecharacter described incorporating a display on the transmitter forindicating the completion of a desired action by a receiver ortransceiver in a closed loop system.

Further objects and advantages of the invention will become apparentfrom a consideration of the drawings and ensuing description thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation view showing the details of construction of aflextensional piezoelectric transducer used in the present invention, asan electroactive generator;

FIG. 1 a is an elevation view showing the details of construction of theflextensional piezoelectric generator of FIG. 1 having an additionalprestress layer;

FIG. 2 is an elevation view showing the details of construction of analternate multi-layer flextensional piezoelectric generator used in amodification of the present invention;

FIG. 2 a is an elevation view showing the details of construction of theflextensional piezoelectric generator of FIG. 1 a with a flat ratherthan arcuate profile;

FIG. 3 is an elevation view of an embodiment of a device for mechanicalapplication and removal of a force to the center of an electroactivegenerator;

FIG. 4 is an elevation view of the device of FIG. 3 illustrating thedeformation of the electroactive generator upon application of a force;

FIG. 5 is an elevation view of the device of FIG. 3 illustrating therecovery of the electroactive generator upon removal of the force bytripping of a quick-release device;

FIG. 6 is an elevation view of the actuating device of the presentinvention for generation of an electrical signal by deflecting aflextensional piezoelectric transducer;

FIG. 7 is an elevation view of the preferred mounting and actuatingdevice of the present invention for generation of an electrical signalby deflecting a flextensional piezoelectric transducer;

FIG. 8 is an elevation view of an alternate mounting and actuatingdevice of the present invention for generation of an electrical signalby deflecting a flextensional piezoelectric transducer of FIG. 2 a;

FIGS. 9 a-9 c show an alternate clamping mechanism for retention of anend of a flextensional piezoelectric transducer in undeflected anddeflected states;

FIGS. 10 a-c show the electrical signal generated by the transducer, theelectrical output signal of the rectifier at the junction with thecapacitor and the regulated electrical signal respectively;

FIGS. 11 a and 11 b are elevation views of the preferred deflectorassembly of the present invention showing the transducer in theundeflected and deflected positions respectively;

FIG. 11 c is a plan view of the preferred deflector assembly of thepresent invention showing the transducer in the undeflected position;

FIGS. 12 a-e are elevation views of one embodiment of a plucker paddlemechanism as in FIGS. 11 a-c, deflecting the end of an electroactivegenerator, and rotating/cocking to a reset position;

FIGS. 13 a-b are a plan views of a multifunction switch incorporatingthe actuating mechanism of FIGS. 11 a-c (shown in ghost in FIG. 13 b);

FIG. 14 is a plan view of an alternate embodiment of a deflectorassembly and casing which enclose the transducer of the presentinvention;

FIG. 15 is a plan view of an alternate embodiment of a deflectorassembly using a sliding paddle;

FIGS. 16 a-c are elevational cross-sections taken along line 16-16 ofFIG. 14;

FIGS. 17 a-d are elevational cross-sections taken along line 17-17 ofFIG. 15;

FIG. 18 is an elevation view of a linear magnetic microgenerator;

FIG. 19 is an elevation view of a rotary magnetic microgenerator;

FIG. 20 is a block diagram showing the components of a circuit for usingthe electrical signal generated by the device of FIGS. 6-8, and 11-19;

FIG. 21 is a block diagram showing the components of an alternatecircuit for using the electrical signal generated by the device of FIGS.6-8, and 11-19;

FIG. 22 is a detailed circuit diagram of the circuit in FIG. 20;

FIG. 23 is a detailed circuit diagram of the circuit in FIG. 21;

FIG. 24 is a detailed circuit diagram of an alternate circuit in FIG.21;

FIG. 25 is a block diagram showing the components of an alternatecircuit for using the electrical signal generated by the device of FIGS.6-8 and 13 a-b and incorporating membrane switches for multiplefunctions;

FIG. 26 is a plan view of a domed contact switch showing disconnectedconcentric circuit traces, with the domed contact in ghost thereabove;and

FIG. 27 is a plan view of a contact switch showing disconnectedinterdigitated circuit traces, with the shorting contact in ghostthereabove.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Electroactive Generator

Piezoelectric and electrostrictive materials (generally called“electroactive” devices herein) develop an electric field when placedunder stress or strain. The electric field developed by a piezoelectricor electrostrictive material is a function of the applied force anddisplacement causing the mechanical stress or strain. Conversely,electroactive devices undergo dimensional changes in an applied electricfield. The dimensional change (i.e., expansion or contraction) of anelectroactive element is a function of the applied electric field.Electroactive devices are commonly used as drivers, or “actuators” dueto their propensity to deform under such electric fields. Theseelectroactive devices when used as transducers or generators also havevarying capacities to generate an electric field in response to adeformation caused by an applied force. In such cases they behave aselectrical generators.

Electroactive devices include direct and indirect mode actuators, whichtypically make use of a change in the dimensions of the material toachieve a displacement, but in the present invention are preferably usedas electromechanical generators. Direct mode actuators typically includea piezoelectric or electrostrictive ceramic plate (or stack of plates)sandwiched between a pair of electrodes formed on its major surfaces.The devices generally have a sufficiently large piezoelectric and/orelectrostrictive coefficient to produce the desired strain in theceramic plate. However, direct mode actuators suffer from thedisadvantage of only being able to achieve a very small displacement(strain), which is, at best, only a few tenths of a percent. Conversely,direct mode generator-actuators require application of a high amount offorce to piezoelectrically generate a pulsed momentary electrical signalof sufficient magnitude to activate a latching relay.

Indirect mode actuators are known to exhibit greater displacement andstrain than is achievable with direct mode actuators by achieving strainamplification via external structures. An example of an indirect modeactuator is a flextensional transducer. Flextensional transducers arecomposite structures composed of a piezoelectric ceramic element and ametallic shell, stressed plastic, fiberglass, or similar structures. Theactuator movement of conventional flextensional devices commonly occursas a result of expansion in the piezoelectric material whichmechanically couples to an amplified contraction of the device in thetransverse direction. In operation, they can exhibit several orders ofmagnitude greater strain and displacement than can be produced by directmode actuators.

The magnitude of achievable deflection (transverse bending) of indirectmode actuators can be increased by constructing them either as“unimorph” or “bimorph” flextensional actuators. A typical unimorph is aconcave structure composed of a single piezoelectric element externallybonded to a flexible metal foil, and which results in axial buckling(deflection normal to the plane of the electroactive element) whenelectrically energized. Common unimorphs can exhibit transverse bendingas high as 10%, i.e., a deflection normal to the plane of the elementequal to 10% of the length of the actuator. A conventional bimorphdevice includes an intermediate flexible metal foil sandwiched betweentwo piezoelectric elements. Electrodes are bonded to each of the majorsurfaces of the ceramic elements and the metal foil is bonded to theinner two electrodes. Bimorphs exhibit more displacement than comparableunimorphs because under the applied voltage, one ceramic element willcontract while the other expands. Bimorphs can exhibit transversebending of up to 20% of the Bimorph length.

For certain applications, asymmetrically stress biased electroactivedevices have been proposed in order to increase the transverse bendingof the electroactive generator, and therefore increase the electricaloutput in the electroactive material. In such devices, (which include,for example, “Rainbow” actuators (as disclosed in U.S. Pat. No.5,471,721), and other flextensional actuators) the asymmetric stressbiasing produces a curved structure, typically having two majorsurfaces, one of which is concave and the other which is convex.

Thus, various constructions of flextensional piezoelectric andferroelectric generators may be used including: indirect mode actuators(such as “moonies” and CYMBAL); bending actuators (such as unimorph,bimorph, multimorph or monomorph devices); prestressed actuators (suchas “THUNDER” and “rainbow” actuators as disclosed in U.S. Pat. No.5,471,721); and multilayer actuators such as stacked actuators; andpolymer piezofilms such as PVDF. Many other electromechanical devicesexist and are contemplated to function similarly to power a transmitter,receiver and/or transceiver circuit in the present invention.

Referring to FIG. 1: The electroactive generator preferably comprises aprestressed unimorph device called “THUNDER”, which has improveddisplacement and load capabilities, as disclosed in U.S. Pat. No.5,632,841. THUNDER (which is an acronym for THin layer compositeUNimorph ferroelectric Driver and sEnsoR), is a unimorph device in whicha pre-stress layer is bonded to a thin piezoelectric ceramic wafer athigh temperature. During the cooling down of the composite structure,asymmetrical stress biases the ceramic wafer due to the difference inthermal contraction rates of the pre-stress layer and the ceramic layer.A THUNDER element comprises a piezoelectric ceramic layer bonded with anadhesive (preferably an imide) to a metal (preferably stainless steel)substrate. The substrate, ceramic and adhesive are heated until theadhesive melts and they are subsequently cooled. During cooling as theadhesive solidifies the adhesive and substrate thermally contracts morethan the ceramic, which compressively stresses the ceramic. Using asingle substrate, or two substrates with differing thermal andmechanical characteristics, the actuator assumes its normally arcuateshape. The transducer or electroactive generator may also be normallyflat rather than arcuate, by applying equal amounts of prestress to eachside of the piezoelectric element, as dictated by the thermal andmechanical characteristics of the substrates bonded to each face of thepiezo-element.

The THUNDER element 12 is as a composite structure, the construction ofwhich is illustrated in FIG. 1. Each THUNDER element 12 is constructedwith an electroactive member preferably comprising a piezoelectricceramic layer 67 of PZT which is electroplated 65 and 65 a on its twoopposing faces. A pre-stress layer 64, preferably comprising springsteel, stainless steel, beryllium alloy, aluminum or other flexiblesubstrate (such as metal, fiberglass, carbon fiber, KEVLAR™, compositesor plastic), is adhered to the electroplated 65 surface on one side ofthe ceramic layer 67 by a first adhesive layer 66. In the simplestembodiment, the adhesive layer 66 acts as a prestress layer. The firstadhesive layer 66 is preferably LaRC™-SI material, as developed byNASA-Langley Research Center and disclosed in U.S. Pat. No. 5,639,850. Asecond adhesive layer 66 a, also preferably comprising LaRC-SI material,is adhered to the opposite side of the ceramic layer 67. Duringmanufacture of the THUNDER element 12 the ceramic layer 67, the adhesivelayer(s) 66 and 66 a and the pre-stress layer 64 are simultaneouslyheated to a temperature above the melting point of the adhesivematerial. In practice the various layers composing the THUNDER element(namely the ceramic layer 67, the adhesive layers 66 and 66 a and thepre-stress layer 64) are typically placed inside of an autoclave, heatedplaten press or a convection oven as a composite structure, and slowlyheated under pressure by convection until all the layers of thestructure reach a temperature which is above the melting point of theadhesive 66 material but below the Curie temperature of the ceramiclayer 67. Because the composite structure is typically convectivelyheated at a slow rate, all of the layers tend to be at approximately thesame temperature. In any event, because an adhesive layer 66 istypically located between two other layers (i.e. between the ceramiclayer 67 and the pre-stress layer 64), the ceramic layer 67 and thepre-stress layer 64 are usually very close to the same temperature andare at least as hot as the adhesive layers 66 and 66 a during theheating step of the process. The THUNDER element 12 is then allowed tocool.

During the cooling step of the process (i.e. after the adhesive layers66 and 66 a have re-solidified) the ceramic layer 67 becomescompressively stressed by the adhesive layers 66 and 66 a and pre-stresslayer 64 due to the higher coefficient of thermal contraction of thematerials of the adhesive layers 66 and 66 a and the pre-stress layer 64than for the material of the ceramic layer 67. Also, due to the greaterthermal contraction of the laminate materials (e.g. the first pre-stresslayer 64 and the first adhesive layer 66) on one side of the ceramiclayer 67 relative to the thermal contraction of the laminate material(s)(e.g. the second adhesive layer 66 a) on the other side of the ceramiclayer 67, the ceramic layer deforms in an arcuate shape having anormally convex face 12 a and a normally concave face 12 c, asillustrated in FIGS. 1 and 2.

Referring to FIG. 1 a: One or more additional pre-stressing layer(s) maybe similarly adhered to either or both sides of the ceramic layer 67 inorder, for example, to increase the stress in the ceramic layer 67 or tostrengthen the THUNDER element 12B. In a preferred embodiment of theinvention, a second prestress layer 68 is placed on the concave face 12a of the THUNDER element 12B having the second adhesive layer 66 a andis similarly heated and cooled. Preferably the second prestress layer 68comprises a layer of conductive metal. More preferably the secondprestress layer 68 comprises a thin foil (relatively thinner than thefirst prestress layer 64) comprising aluminum or other conductive metal.During the cooling step of the process (i.e. after the adhesive layers66 and 66 a have re-solidified) the ceramic layer 67 similarly becomescompressively stressed by the adhesive layers 66 and 66 a and pre-stresslayers 64 and 68 due to the higher coefficient of thermal contraction ofthe materials of the adhesive layers 66 and 66 a and the pre-stresslayers 64 and 68 than for the material of the ceramic layer 67. Also,due to the greater thermal contraction of the laminate materials (e.g.the first pre-stress layer 64 and the first adhesive layer 66) on oneside of the ceramic layer 67 relative to the thermal contraction of thelaminate material(s) (e.g. the second adhesive layer 66 a and the secondprestress layer 68) on the other side of the ceramic layer 67, theceramic layer 67 deforms into an arcuate shape having a normally convexface 12 a and a normally concave face 12 c, as illustrated in FIG. 1 a.

Alternately, the second prestress layer 68 may comprise the samematerial as is used in the first prestress layer 64, or a material withsubstantially the same mechanical strain characteristics. Using twoprestress layers 64, 68 having similar mechanical strain characteristicsensures that, upon cooling, the thermal contraction of the laminatematerials (e.g. the first pre-stress layer 64 and the first adhesivelayer 66,) on one side of the ceramic layer 67 is substantially equal tothe thermal contraction of the laminate materials (e.g. the secondadhesive layer 66 a and the second prestress layer 68) on the other sideof the ceramic layer 67, and the ceramic layer 67 and the transducer 12remain substantially flat, but still under a compressive stress.

Alternatively, the substrate comprising a separate prestress layer 64may be eliminated and the adhesive layers 66 and 66 a alone or inconjunction may apply the prestress to the ceramic layer 67.Alternatively, only the prestress layer(s) 64 and 68 and the adhesivelayer(s) 66 and 66 a may be heated and bonded to a ceramic layer 67,while the ceramic layer 67 is at a lower temperature, in order to inducegreater compressive stress into the ceramic layer 67 when cooling thetransducer 12.

Referring now to FIG. 2: Yet another alternate THUNDER generator element12D includes a composite piezoelectric ceramic layer 69 that comprisesmultiple thin layers 69 a and 69 b of PZT which are bonded to each otheror cofired together. In the mechanically bonded embodiment of FIG. 2,two layers 69 a and 69 b, or more (not shown) my be used in thiscomposite structure 12D. Each layer 69 a and 69 b comprises a thin layerof piezoelectric material, with a thickness preferably on the order ofabout 1 mil. Each thin layer 69 a and 69 b is electroplated 65 and 65 a,and 65 b and 65 c on each major face respectively. The individual layers69 a and 69 b are then bonded to each other with an adhesive layer 66 b,using an adhesive such as LaRC-SI. Alternatively, and most preferably,the thin layers 69 a and 69 b may be bonded to each other by cofiringthe thin sheets of piezoelectric material together. As few as two layers69 a and 69 b, but preferably at least four thin sheets of piezoelectricmaterial may be bonded/cofired together. The composite piezoelectricceramic layer 69 may then be bonded to prestress layer(s) 64 with theadhesive layer(s) 66 and 66 a, and heated and cooled as described aboveto make a modified THUNDER transducer 12D. By having multiple thinnerlayers 69 a and 69 b of piezoelectric material in a modified transducer12D, the composite ceramic layer generates a lower voltage and highercurrent as compared to the high voltage and low current generated by aTHUNDER transducer 12 having only a single thicker ceramic layer 67.Additionally, a second prestress layer may be used comprise the samematerial as is used in the first prestress layer 64, or a material withsubstantially the same mechanical strain characteristics as describedabove, so that the composite piezoelectric ceramic layer 69 and thetransducer 12D remain substantially flat, but still under a compressivestress.

Referring now to FIG. 2 b: Yet another alternate THUNDER generatorelement 12E includes another composite piezoelectric ceramic layer 169that comprises multiple thin layers 169 a-f of PZT which are cofiredtogether. In the cofired embodiment of FIG. 2 b, two or more layers 169a-f, and preferably at least four layers, are used in this compositestructure 12E. Each layer 169 a-f comprises a thin layer ofpiezoelectric material, with a thickness preferably on the order ofabout 1 mil, which are manufactured using thin tape casting for example.Each thin layer 169 a-f placed adjacent each other with electrodematerial between each successive layer. The electrode material mayinclude metallizations, screen printed, electro-deposited, sputtered,and/or vapor deposited conductive materials. The individual layers 169a-f and internal electrodes are then bonded to each other by cofiringthe composite multi-layer ceramic element 169. The individual layers 169a-f are then poled in alternating directions in the thickness direction.This is accomplished by connecting high voltage electrical connectionsto the electrodes, wherein positive connections are connected toalternate electrodes, and ground connections are connected to theremaining internal electrodes. This provides an alternating up-downpolarization of the layers 169 a-f in the thickness direction. Thisallows all the individual ceramic layers 169 a-f to be connected inparallel. The composite piezoelectric ceramic layer 169 may then bebonded to prestress layer(s) 64 with the adhesive layer(s) 66 and 66 a,and heated and cooled as described above to make a modified THUNDERtransducer 12D.

Referring again to FIGS. 2, 2 a and 2 b: By having multiple thinnerlayers 69 a and 69 b (or 169 a-f) of piezoelectric material in amodified transducer 12D-F, the composite ceramic layer generates a lowervoltage and higher current as compared to the high voltage and lowcurrent generated by a THUNDER transducer 12 having only a singlethicker ceramic layer 67. This is because with multiple thin paralleledlayers the output capacitance is increased, which decreases the outputimpedance, which pr9ovides better impedance matching with the electroniccircuitry connected to the THUNDER element. Also, since the individuallayers of the composite element are th8inner, the output voltage can bereduced to reach a voltage which is closer to the operating voltage ofthe electronic circuitry (in a range of 3.3V-10.0V) which provides lesswaste in the regulation of the voltage and better matching to thedesired operating voltages of the circuit. Thus the multilayer element(bonded or cofired) improves impedance matching with the connectedelectronic circuitry and improves the efficiency of the mechanical toelectrical conversion of the element.

A flexible insulator may be used to coat the convex face 12 a of thetransducer 12. This insulative coating helps prevent unintentionaldischarge of the piezoelectric element through inadvertent contact withanother conductor, liquid or human contact. The coating also makes theceramic element more durable and resistant to cracking or damage fromimpact. Since LaRC-SI is a dielectric, the adhesive layer 67 a on theconvex face 12 a of the transducer 12 may act as the insulative layer.Alternately, the insulative layer may comprise a plastic, TEFLON orother durable coating.

Electrical energy may be recovered from or introduced to the generatorelement 12 (or 12D) by a pair of electrical wires 14. Each electricalwire 14 is attached at one end to opposite sides of the generatorelement 12. The wires 14 may be connected directly to the electroplated65 and 65 a faces of the ceramic layer 67, or they may alternatively beconnected to the pre-stress layer(s) 64 and or 68. The wires 14 areconnected using, for example, conductive adhesive, or solder 20, butmost preferably a conductive tape, such as a copper foil tape adhesivelyplaced on the faces of the electroactive generator element, thusavoiding the soldering or gluing of the conductor. As discussed above,the pre-stress layer 64 is preferably adhered to the ceramic layer 67 byLaRC-SI material, which is a dielectric. When the wires 14 are connectedto the pre-stress layer(s) 64 and/or 68, it is desirable to roughen aface of the pre-stress layer 68, so that the pre-stress layer 68intermittently penetrates the respective adhesive layers 66 and 66 a,and makes electrical contact with the respective electroplated 65 and 65a faces of the ceramic layer 67. Alternatively, the Larc-SI adhesivelayer 66 may have a conductive material, such as Nickel or aluminumparticles, used as a filler in the adhesive and to maintain electricalcontact between the prestress layer and the electroplated faces of theceramic layer(s). The opposite end of each electrical wire 14 ispreferably connected to an electric pulse modification circuit 10.

Prestressed flextensional transducers 12 are desirable due to theirdurability and their relatively large displacement, and concomitantrelatively high voltage that such transducers are capable of developingwhen deflected by an external force. The present invention however maybe practiced with any electroactive element having the properties andcharacteristics herein described, i.e., the ability to generate avoltage in response to a deformation of the device. For example, theinvention may be practiced using magnetostrictive or ferroelectricdevices. The transducers also need not be normally arcuate, but may alsoinclude transducers that are normally flat, and may further includestacked piezoelectric elements.

In operation, as shown in FIG. 4, when a force indicated by arrow 16 isapplied to the convex face 12 a of the transducer 12, the force deformsthe electroactive layer 67. The force may be applied to the transducer12 by any appropriate means such as by application of manual pressuredirectly to the transducer, or by other mechanical means. Preferably,the force is applied by a mechanical switch (e.g., a plunger, striker,toggle or roller switch) capable of developing a mechanical impulse forapplication to and removal from the transducer 12. The mechanicalimpulse (or removal thereof) is of sufficient force to cause thetransducer 12 to deform quickly and accelerate over a distance(approximately 10 mm), and oscillate between deflected positions aboutthe undeflected position, which generates an electrical signal ofsufficient magnitude to activate downstream circuit components foroperation of an electromechanical latching relay, or generation of an RFtransmission to activate a receiver which operates the electromechanicallatching relay.

Referring to FIGS. 3, 4 and 5: An illustration of prior means forgenerating an electrical pulse by application of mechanical forcecomprises a switch plate 18 and a plunger assembly 13. The two ends ofthe piezoelectric transducer 12 are each pivotably held in place withina recess 44 of a switch plate 18. The switch plate 18 is the same shapeas the transducer 12 contained therein, preferably rectangular.Alternatively, a circular transducer 12 is mounted in a circular recessof a circular switch plate. The recess(es) 44 in the switch plate 18hold the transducer 12 in place in its relaxed, i.e., undeformed state.The recesses 44 are also sufficiently deep to fully receive the ends oredges of the transducer 12 in its fully deformed, i.e., flat state. Theplunger assembly comprises a push button 22 pivotably connected to ahinged quick-release mechanism 24. The opposite end of the quick-releasemechanism 24 contacts shaft 26 connected to a pair of plates 27 and 28which are clamped on both sides of the transducer 12. A release cog 25is located along the path of the quick-release mechanism 24.

In operation, when the push button 22 is depressed in the direction ofarrow 16, the quick-release mechanism 24 pushes down on the shaft 26 andplates 27 and 28 and deforms the transducer 12. When the quick-releasemechanism 24 reaches the release cog 25, the quick-release mechanism 24pivots on its hinge and releases the downward pressure from the shaft26, plates 27 and 28 and transducer 12. The transducer 12, on account ofthe restoring force of the substrate of the prestress layer 64, returnsquickly to its undeformed state in the direction of arrow 30 as in FIG.5.

As previously mentioned, the applied force causes the piezoelectrictransducer 12 to deform. By virtue of the piezoelectric effect, thedeformation of the piezoelectric element 67 generates an instantaneousvoltage between the faces 12 a and 12 c of the transducer 12, whichproduces a pulse of electrical energy. Furthermore, when the force isremoved from the piezoelectric transducer 12, the transducer 12 recoversits original arcuate shape. This is because the bending of the substrate(and attached layers) stores mechanical (spring) energy which isreleased upon removal of the force. Additionally, the substrate orprestress layers 64 and 68 to which the ceramic 67 is bonded exert acompressive force on the ceramic 67, and the transducer 12 thus has anadditional restoring force that causes the transducer 12 to return toits undeformed neutral state. On the recovery stroke of the transducer12, the ceramic 67 returns to its undeformed state and thereby producesanother electrical pulse of opposite polarity. The downward (applied) orupward (recovery) strokes cause a force over a distance that is ofsufficient magnitude to create the desired electrical pulse. Theduration of the recovery stroke, and therefore the duration of the pulseproduced, is preferably in the range of 50-100 milliseconds, dependingon the mechanical properties of the transducer, including its naturalfrequency of vibration.

Referring to FIG. 6: In the preferred embodiment of the invention, thetransducer 12 is clamped at one end 121 and the mechanical impulse isapplied to the edge on the free end 122, i.e., at the end opposite tothe clamped end 121 of the transducer 12. By applying the force to theedge on the free end 122 of the transducer 12 and releasing it, theactuator oscillates between the release position, to another positionpast the undeformed position, and then dampedly oscillates between thedeformed positions returning to the undeformed position, by virtue ofthe substrates (spring steel) restoring force. Therefore, the electricalpulse that is generated upon removal of the force is an oscillating wave(rather than a single pulse as with the prior actuating means disclosedabove).

Referring again to FIG. 6: FIG. 6 illustrates one embodiment of a devicefor generating an oscillating electrical signal by application ofmechanical force to an end 122 of the transducer 12. This devicecomprises a transducer 12 mounted between a base plate 70 and a clampingmember 75 as well as a deflector assembly 72. The base plate 70 ispreferably of substantially the same shape (in plan view) as thetransducer 12 attached thereon, and most preferably rectangular. One end121 of the piezoelectric transducer 12 is held in place between theclamping member 75 and the upper surface 70 a of a base plate 70,preferably on one end thereof. The clamping member 75 comprises a plateor block having a lower surface 75 a designed to mate with the uppersurface 70 a of the base plate 70 with the transducer 12 therebetween.The device also has means for urging 76 the mating surface 75 a of theclamping block towards the upper surface 70 a of the base plate 70. Thisallows the lower surface 75 a of the clamping plate 75 to besubstantially rigidly coupled to the upper surface 70 a of the baseplate 70, preferably towards one side of the switch plate 70. The meansfor urging 76 together the mating surfaces 70 a and 75 a of the baseplate 70 and clamping plate 75 may comprise screws, clamping jaws orsprings or the like. Most preferably the urging means 76 comprises atleast one screw 76 passing through the clamping member 75 and into ascrew hole 77 in the upper surface 70 a of the base plate 70.

One end 121 of a transducer 12 is placed between the mating surfaces 70a and 75 a of the base and clamping plates 70 and 75. The matingsurfaces 70 a and 75 a are then urged towards each other with the screw76 to rigidly hold the end 121 of the transducer 12 in place between thebase and clamping plates 70 and 75 with the opposite end 122 of thetransducer 12 free to be moved by a mechanical impulse applied manuallyor preferably by a deflector assembly 72. The transducer 12 may furtherbe aligned and securely retained between the base plate 70 and clampingplate 75 by means of one or more pins (not shown) on the base plate 70and/or clamping plate 75 and holes (not shown) in the end 121 of thetransducer 12.

Referring now to FIG. 7: In the preferred embodiment of the inventionthe surfaces 70 a and 75 a of the base and clamping plate 70 and 75 aredesigned to best distribute pressure evenly along the end 121 of thetransducer 12 therebetween. To this end the upper surface 70 a of thebase plate 70 contacting the end 121 of the transducer 12 is preferablysubstantially flat and lower surface 75 a of the clamping member 75preferably has a recess 74 therein which accommodates insertion of thetransducer end 121 therein. Preferably the depth of the recess 74 isequal to half the thickness of the transducer substrate 64, but may beas deep as the substrate thickness. Thus, the end 121 of the transducer12 may be placed between the recess 74 and the upper surface 70 a of thebase plate 70 and secured therebetween by the screw 76. Alternatively,either or both of the mating surfaces 70 a and 75 a of the base andclamping plates 70 and 75 may have a recess therein to accommodateinsertion and retention of the end 121 of the transducer 12therebetween. The portion of the bottom surface 75 a of the clampingmember 75 beyond the recess 74 has no contact with the transducer 12,and is that portion through which the screw 76 passes. This portion ofthe bottom surface 75 a may contact the upper surface 70 a of the baseplate 70, but most preferably there is a small gap (equal to thedifference of the substrate thickness and the recess depth) between thelower surface 75 a of the clamping member 75 and the top surface 70 a ofthe base plate 70 when the transducer 12 is inserted therebetween. Inyet another embodiment of the invention, the mating surfaces 70 a and 75a of the base and clamping plates 70 and 75 may be adhesively bondedtogether (rather than screwed) with the end 121 of the transducer 12sandwiched therebetween. In yet another alternative embodiment of thedevice, the clamping member 75 and base plate 70 may comprise a singlemolded structure having a central slot into which may be inserted oneend 121 of the transducer 12.

The clamping assembly 75 holds the transducer 12 in place in itsrelaxed, i.e., undeformed state above the base plate 70 with the freeend 122 of the transducer 12 in close proximity to a deflector 72assembly. More specifically, the transducer 12 is preferably clampedbetween the mating surfaces 70 a and 75 a of the base and clampingplates 70 and 75 with the convex face 12 a of the transducer 12 facingthe base plate 70. Since the transducer 12 in its relaxed state isarcuate, the convex face 12 a of the transducer 12 curves away from theupper surface 70 a of the base plate 70 while approaching the free end122 of the transducer 12. Mechanical force may then be applied to thefree end 122 of the transducer 12 in order to deform the electroactiveelement 67 to develop an electrical signal.

Because of the composite, multi-layer construction of the transducer 12it is important to ensure that the clamping member 75 not only holds thetransducer 12 rigidly in place, but also that the transducer 12 is notdamaged by the clamping member 75. In other words, the transducer 12,and more specifically the ceramic layer 67, should not be damaged by theclamping action of the clamping member 75 in a static mode, butespecially in the dynamic state when applying a mechanical impulse tothe transducer 12 with the plunger 72. For example, referring to FIG. 6,when a mechanical impulse is applied to the transducer 12 in thedirection of arrow 81, the bottom corner of the ceramic (at point C)contacts the base plate 70 and is further pushed into the base plate,which may crack or otherwise damage the ceramic layer 67.

Referring again to FIG. 7: It has been found that the tolerances betweenthe mating surfaces 75 a and 70 a of the clamping and base plates 75 and70 are very narrow. It has also been found that application of adownward force (as indicated by arrow 81) to the free end 122 of thetransducer 12 would cause the ceramic element 67 of the transducer 12 tocontact the upper surface 70 a of the base plate 70, thereby making morelikely damage to the ceramic 67. Therefore, in the preferred embodimentof the invention, the base plate 70 has a recessed area 80 in its uppersurface 70 a which not only protects the electroactive element 67 fromdamage but also provides electrical contact to the convex face 12 a ofthe transducer 12 so that the electrical signal developed by thetransducer 12 may be applied to downstream circuit elements.

As can be seen in FIG. 7, one end 121 of the transducer 12 is placedbetween the surfaces 75 a and 70 a of the clamping and base plates 75and 70 such that only the substrate 64 contacts both surface 75 a and 70a. The clamping plate 75 preferably contacts the concave surface 12 b ofthe transducer 12 along the substrate 64 up to approximately the edge ofthe ceramic layer 67 on the opposite face 12 a of the transducer 12. Theclamping member may however extend along the convex face 12 c furtherthan the edge C of the ceramic layer 67 in order to apply greater ormore even pressure to the transducer 12 surfaces 12 a and 12 c betweenthe clamping member 75 and base plate 70. The ceramic layer 67 whichextends above the surface of the substrate 64 on the convex face 12 aextends into the recessed area 80 of the switch plate 70. This preventsthe ceramic layer 67 from contacting the upper surface 70 a of the baseplate 70, thereby reducing potential for damage to the ceramic layer 67.

The recess 80 is designed not only to prevent damage to the ceramiclayer 67, but also to provide a surface along which electrical contactcan be maintained with the electrode 68 on the convex face of thetransducer 12. The recess 80 extends into the base plate 70 and has avariable depth, preferably being angled to accommodate the angle atwhich the convex face 12 a of the transducer 12 rises from the recess 80and above the top surface 70 a of the base plate 70. More specifically,the recess 80 preferably has a deep end 81 and a shallow end 82 with itsmaximum depth at the deep end 81 beneath the clamping member 75 andsubstrate 12 just before where the ceramic layer 67 extends into therecess 80 at point C. The recess 80 then becomes shallower in thedirection approaching the free end 122 of the transducer 12 until itreaches its minimum depth at the shallow end 82.

The recess 80 preferably contains a layer of compliant material 85(preferably rubber, but alternately cork, urethane, silicone, felt orthe like) along its lower surface which helps prevent the ceramic layer67 from being damaged when the transducer 12 is deformed and the loweredge C of the ceramic layer 67 is pushed into the recess 80. Preferablythe compliant layer 85 is of substantially uniform thickness along itslength, the thickness of the compliant layer 85 being substantiallyequal to the depth of the recess 80 at the shallow end 82. The length ofthe compliant layer 85 is preferably slightly shorter than the length ofthe recess 80 to accommodate the deformation of the compliant layer 85when the transducer 12 is pushed into the recess and compliant layer 85.

The compliant layer 85 preferably has a flexible electrode layer 90overlying it to facilitate electrical contact with the aluminum layer 68on the ceramic layer 67 on the convex face 12 a of the transducer 12.More preferably, the electrode layer 90 comprises a layer of copperoverlaying a layer of KAPTON film, as manufactured by E.I. du Pont deNemours and Company, bonded to the compliant layer 85 with a layer ofadhesive, preferably CIBA adhesive. The electrode layer 90 preferablyextends completely across the compliant layer 85 from the deep end 81 tothe shallow end 82 of the recess 80 and may continue as far as desiredbeyond the recess 80 along the top surface 70 a of the base plate 70.

In the preferred embodiment of the invention, the end 121 of thetransducer 12 is not only secured between the clamping plate 75 and thebase plate 70, but the second prestress layer 68 covering the ceramiclayer 67 of the transducer 12 is in constant contact with the electrodelayer 90 in the recess 80 at all times, regardless of the position ofthe transducer 12 in its complete range of motion. To this end, thedepth of the recess 80 (from the top surface 70 a to the electrode 90)is at least equal to a preferably slightly less than the thickness ofthe laminate layers (adhesive layers 66, ceramic layer 67 and prestresslayer 68) extending into the recess 80. The electrode layer ispreferably adhered to either or both the aluminum layer 68 and thecompliant layer 85, with a suitable adhesive, including for example,conductive adhesives.

An assembly was built having the following illustrative dimensions. Thetransducer 12 comprised a 1.59 by 1.79 inch spring steel substrate thatwas 8 mils thick. A 1-1.5 mil thick layer of adhesive having a nickeldust filler in a 1.51 inch square was placed one end of the substrate0.02 inch from three sides of the substrate (leaving a 0.25 inch tab onone end 121 of the transducer 12). An 8-mil thick layer of PZT-5A typepiezoelectric material in a 1.5 inch square was centered on the adhesivelayer. A 1-mil thick layer of adhesive (with no metal filler) was placedin a 1.47 inch square centered on the PZT layer. Finally, a 1-mil thicklayer of aluminum in a 1.46 inch square was centered on the adhesivelayer. The tab 121 of the transducer 12 was placed in a recess in aclamping block 76 having a length of 0.375 inch and a depth of 4 mils.The base plate 70 had a 0.26 in long recess 80 where the deep end 81 ofthe recess had a depth of 20 mils and tapered evenly to a depth of 15mils at the shallow end 82 of the recess 80. A rubber compliant layer 85having a thickness of 15 mils and a length of 0.24 inches was placed inthe recess 80. An electrode layer of 1 mil copper foil overlying 1 milKAPTON tape was adhered to the rubber layer and extended beyond therecess 1.115 inches. The clamping member 75 was secured to the baseplate 70 with a screw 76 and the aluminum second prestress layer of thetransducer 12 contacted the electrode 90 in the recess 80 substantiallytangentially (nearly parallel) to the angle the transducer 12 therebymaximizing the surface area of the electrical contact between the two.

As shown in FIG. 7, in an alternate embodiment of the invention, aweight 95 may be attached to the free end 122 of the transducer 12. Theaddition of the mass 95 to the free end 122 of the transducer 12,decreases the amount of damping of the oscillation and thereby increasesthe duration of oscillation of the transducer 12 when it was deflectedand released. By having a longer duration and higher overall amplitudeoscillation, the transducer 12 is capable of developing more electricalenergy from its oscillation than an transducer 12 having no additionalmass at its free end 122.

As shown in FIG. 8, in an alternate embodiment of the invention, antransducer 12, 12B, 12D may be mounted in a cantilever fashion. In FIG.8, the transducer 12D pictured is that of FIG. 2A, but other transducers12 or 12B may be similarly mounted. This mount also includes a baseplate 70 and clamping plates 75, 78 for retaining the clamped end 121 ofthe transducer 12 therebetween, as well as deflector 72 mounted to thebase plate 70 in proximity to the free end 122 of the transducer 12. Thelower clamping plate 78 is rigidly connected to the base plate 70 at itslower surface 78 b, and holds the transducer 12 on its top surface 78 aabove the top surface of the base plate 70, which allows the deflector72 to deform the free end 122 of the transducer 12 up to the distanceequal to the lower clamping plate's 78 thickness. The upper clampingplate 75 and lower clamping plate 78 hold the free end 121 of thetransducer 12 therebetween through use of urging means, including thescrew 76 and screw hole 77 pictured. Although the preferred embodimentof the invention uses a screw 76, other means for urging 76 the plates75, 78 together may be used, such as clamping jaws, springs, clips,adhesives and the like.

Referring now to FIGS. 9 a-9 c: An alternate means for clamping thetransducer 12 is shown, wherein each of the clamping plates 175, 177 hasrounded projections thereon, for retaining the transducer 12, yetallowing some bending or the transducer 12 between the plates 175, 177,in order to distribute and reduce point bending forces on the retainedportion 121 of the transducer 12. The clamping plates 175, 177 are urgedtogether, preferably using one or more screws or bolts (not shown). Inthe preferred embodiment of the clamping plates 175, 177, the upperclamping plate 175 has two rounded projections 185, 186 thereon and thelower clamping plate 177 also has two rounded projections 187, 188thereon. Each projection 185-188 is preferably shaped substantially likea half cylinder with the radius of the cylinder extending from themating faces of the clamping plates 175, 177, and in the heightdimension of the half cylinder are substantially perpendicular to thedirection along which the transducer 12 extends from the plates 175,177. The projections are constructed of a rigid, durable material suchas metal or hard plastic. Each of the projections 185, 186 and 187, 188are parallel to each other and equidistant, i.e., projections 185 and186 are parallel and separated by the same distance as parallelprojection 187 and 188. This facilitates placing the end 121 of thetransducer 12 between the projections 185-188 so that the end 121 isretained between the plates 175, 177 along two parallel linescorresponding to the projections 185, 187 and 186, 188 on either side ofthe respective lines. The projections may alternately comprise multiplehemispherical projections, wherein each projection 185-188 comprises twoor more hemispherical projections situated along the same axis as thesemi-cylindrical projections 185-188.

As can be seen in FIGS. 9 a-9 c, when the free end 122 of transducer 12is deflected as shown by arrows 191 and 192, the end 121 of thetransducer 12 between the projections 185-188 is allowed to bend betweenand around the projections 185-188. Furthermore, the rounded shape ofthe projections 185-188 reduces point bending stresses in the transducer12. This is because as the transducer 12 bends, the lines along whichthe projections 185, 187 and 186, 188 retain the transducer 12 actuallyshift slightly off of center (i.e., the apex of the projection) so thatthe transducer 12 is contacted at different points depending upon theamount the transducer 12 is deflected. This configuration allows theretained end 121 of the transducer 12 to bend without point stresses bydistributing the stresses, thereby increasing the durability of thetransducer 12, and also providing less attenuation to the desiredoscillation of the transducer 12 due to the clamping.

Electrical contact to each of the faces 12 a, 12 c of the transducer 12may be provided by use of wires 14 soldered to each face 12 a, 12 c.Alternately, conductive foil may be adhered to each face 12 a, 12 c ofthe transducer 12. As yet another alternative, by using metallicprojections 185-188 on the clamping plates 175, 177, electrical contactwith each of the faces 12 a, 12 c of the transducer 12 may bemaintained, and conductors 14 may be attached to one or both of theprojections 185, 186 and 187, 188 on each side 12 a, 12 c of thetransducer 12, or alternately to the projections 185, 186 and 187, 188via each of the plates 175, 177. By making electrical connections toconductive projections 185-188, bending and point stresses areeliminated from the conductors 14 electrically connected to each face 12a, 12 c of the transducer 12 as it is bent.

Referring to FIGS. 6-8: As mentioned above, it is desirable to generatean electrical signal by deforming the transducer 12. Deformation of thetransducer 12 may be accomplished by any suitable means such as manuallyor by mechanical deflection means such as a plunger, lever or the like.In FIGS. 6-8 a simple deflector 72 is mounted to the base plate 70 inproximity to the free end 122 of the transducer 12. This deflectorassembly 72 includes a lever 86 having first and second ends 87 and 88.The lever is pivotably mounted between the two ends 87 and 88 to afulcrum 89. By exerting a force on the first end 87 of the lever 86 inthe direction of arrow 91, the lever pivots about the fulcrum 89 andapplies a mechanical impulse in the direction of arrow 81 to the freeend 122 of the transducer 12. Alternatively, the lever 86 may be movedopposite the direction of arrow 91 and the transducer 12 may thus bedeflected in the direction opposite arrow 81.

Referring now to FIGS. 11 a-c: FIGS. 11 a-c show the preferredembodiment of a base plate 70 with a deflector assembly 72 andcontaining the transducer 12. The transducer 12 is mounted as in FIG. 7,with one end 121 of the transducer 12 placed between the surfaces theclamping and base plates 75 and 70 such that the substrate 64 contactsboth surfaces 75 a and 70 a. Alternately, the end 121 of the transducer12 may be mounted between clamping plates 185, 187 as shown in FIGS. 9a-c. The ceramic layer 67 which extends above the surface of thesubstrate 64 on the convex face 12 a extends into the recessed area 80of the base plate 70. This prevents the ceramic layer 67 from contactingthe upper surface 70 a of the base plate 70, and cushions the ceramiclayer 67 against the compliant layer 85 in the recess 80, therebyreducing potential for damage to the ceramic layer 67. A deflectorassembly 72 is mounted on the base plate 70 above and to the sides ofthe transducer 12. This deflector assemble 72 has a lower profile thanpreviously described deflector assemblies 72 by virtue of the use of twocooperating counter-rotating lever assembles 260, 270 and a pluckerassembly 300.

Referring again to FIGS. 11 a-c: The deflector assembly comprises aswing arm 260, which is essentially a first lever mounted above theclamped end 121 of the transducer 12 and tending towards the free end122. The swing arm 260 preferably has two pivot arms 261 and 262connected by a cross bar 265. The pivot arms 261 and 262 tend from abovethe clamped end 121 of the transducer 12 and tending towards the freeend 122 of the transducer 12, along each side of the transducer 12 toprevent contact therebetween. A first end 261 a, 262 a of each pivot arm261, 262 is connected to the two ends of a cross bar 265, which issituated above the clamping plate 75. Each pivot arm 261, 262, has a pin264 extending outwardly from the transducer 12, located centrally on thepivot arms 261, 262. The pins are pivotably mounted within fulcrum clips268, which allows the swing arm assembly 260 to pivot about the pins 264and the fulcrum clips 268. The ends 261 b, 262 b of the pivot arms 261,262 opposite the crossbar 265 are preferably upwardly curved to tendsubstantially vertically, or more preferably slightly off vertical andtowards the free end 122 of the transducer 12 and rocker arm 270assemblies. The curved ends 261,b, 262 b of the pivot arms 261, 262 mayalternately be C-shaped, i.e., first curve downwardly (towards the baseplate 70, and then upwardly. To accommodate the downward curve of thepivot arm ends 261 b, 262 b, the base plate 70 may contain recesses (notshown) within which the curved ends 261 b, 262 b may housed.

Referring again to FIGS. 11 a-c: The deflector assembly also comprises arocker assembly 270, which is essentially a pair of second levers 271,272 mounted above the free end 122 of the transducer 12 and tendingtowards and beyond the free end 122. The rocker assembly 270 preferablyhas two rocker arms 271 and 272 pivotably mounted to contact both thepivot arms 261, 262 and the plucker assembly 300. The rocker arms 271and 272 tend from above the curved ends 261 b, 262 b of the pivot arms261, 262 and tend towards and slightly beyond the free end 122 of thetransducer 12, and along each side of the transducer 12 to preventcontact therebetween. Each of the rocker arms 271, 271 has a pin 274thereon, extending outwardly from the transducer 12. Each of these pins274 is pivotably mounted within a pivot hole 278 of the plucker housing290. This allows each rocker arm 271, 272, to rotate about itsrespective pin 274 in response to a force on either end 271 a, 272 a,271 b, 272 b of the rocker arm 271, 272. Each first end 271 a, 272 a ofthe rocker arms 271, 272 is in contact with the second ends 261 b, 262 bof the pivot arms 261, 262. When the crossbar 265 is depressed, thesecond ends 261 b, 262 b of the pivot arms 261, 262 move upwardly andcontact the first ends 271 a, 272 a of the rocker arms 271, 272, causingthe rocker arms 271, 272 to rotate about the rocker arm pins 274. Thiscauses the second ends 271 b, 272 b of the rocker arms 271, 272 to bedepressed.

Referring again to FIGS. 11 a-c: The deflector assembly also comprises aplucker assembly 300, which is essentially a slidably mounted curvedpaddle situated above the free end 122 of the transducer 12. The pluckerassembly 300 is in contact with the rocker assembly 270 and is adaptedto side downwardly within a pair of grooves in response to a downwardmotion from the second ends 271 b, 272 b of the rocker arms 271, 272.More specifically, the plucker assembly 300 comprises a plucker paddle301, situated above and in contact with the free end 122 of thetransducer 12. Connected to each end 301 a, 301 b of the plucker paddle301 is a roller 305, which is in contact with the rocker arms 271, 272.Tending outwardly from each roller 305 is a slide pin 304. The slidepins 304 are slidably mounted within slide grooves 308 in the pluckerhousings 290. The slide grooves 308 tend from a maximum verticalposition and downwardly away from the free end 122 of the transducer 12to a minimum position beyond the free end 122 of the transducer 12.Thus, when the plucker assembly 300 is moved downwardly, the slide pins304 and slide grooves 308 cause the plucker paddle 301 to movesimultaneously downward and away from the free end of 122 the transducer12.

Thus, when the crossbar 265 is depressed, the second ends 261 b, 262 bof the pivot arms 261, 262 move upwardly and contact the first ends 271a, 272 a of the rocker arms 271, 272, causing the rocker arms 271, 272to rotate about the rocker arm pins 274. This causes the second ends 271b, 272 b of the rocker arms 271, 272 to be depressed. As the second ends271 b, 272 b of the rocker arms 271, 272 are depressed, they contact therollers 305 with a downward force, and the plucker assembly 300 isguided by the slide pins 304 and slide grooves 308 to cause the pluckerpaddle 301 to move simultaneously downward and away from the free end of122 the transducer 12. The minimum or lowest position of the pluckerassembly is beyond the free end 122 of the transducer 12, and therefore,as the plucker paddle 301 moves downward and outward, the free end 122of the transducer 12 is released by the plucker paddle 301. Thus as theplucker assembly is depressed, the free end 122 of the transducer 12 isdepressed from its neutral position 291 to a deflected position 292 atwhich position the paddle 301 releases the free end 122 of thetransducer 12. The free end 122 of the transducer 12 then oscillatesbetween positions 291 and 292.

Referring now to FIG. 11 c: The plucker paddle 301 preferably has anedge 301 a that contacts the free end 122 of the transducer 12 that hasa radius in both in the thickness dimension (i.e., verticallycorresponding to the thickness of the transducer 12 edge) and thetransverse dimension (i.e., horizontally corresponding to the length ofthe transducer 12 edge) in order to advantageously release the free end122 very quickly, i.e., without dragging across the end 122 of thetransducer 12, which slows its release. It has been found that the morequickly and cleanly you release the end 122 of the transducer 12 duringa “pluck”, the greater the output. This increases output withoutincreasing the required plucking force. To be precise, the energydeveloped by the piezoelectric element 67 has been found to be afunction of the acceleration of the piezoelectric element 67, ratherthan the speed of the “pluck.” It is possible “pluck” very slowly, andget excellent performance, so long as the piezoelectric element 67 isreleased fully and completely and as nearly instantly as possible. Todetermine the desired shape of the tip 301 a of the plucker paddle 301,several plucker paddles were designed and released very, very slowly, inattempting to get a quick “release” of the end 122 of the transducer 12.If the plucker paddle 301 did not have a radius on the tip, but insteadhad a rectangular shape, it was found that the end 301 a of the pluckerpaddle 301 (the thickness dimension) actually “dragged” across the edge122 of the transducer 12, slowing the release, and decreasing theelectrical output. Thus, increasing the rate of “release” of theelement's edge 122 improved the acceleration and the output. Thus, theradius of the tip 301 a (in the thickness dimension) of the “plucker”paddle 301 contributes substantially to how quickly the transducer 12edge 122 gets off the paddle. This has been shown to have a directeffect on electrical performance, because a smaller radius equates to aquicker “release” which equates to greater electrical output. If thepaddle 301 is manufactured from sufficiently hard materials, or ishardened, the edge 301 a of the paddle 301 can be made with an evensmaller radius. The tip 301 a of the plucking paddle 301 may be coatedwith a very hard material with low friction, thereby lowering theplucking resistance. This approach can prove to be useful in increasingthe power output of a transducer 12 without increasing the requireddisplacement or amount of bending, and may allow the generation of thesame amount of energy with lower “button force” by the user of thedevice, as well as being useful in increasing wear resistance forapplications requiring many hundreds of thousands of switch cycles.

The transducer 12 is typically is curved along its length, i.e., thelongitudinal dimension and this curvature allows the element 12 to bebent or “plucked” substantially before it reaches a flattened state. Thetransducer 12 is also curved across its transverse dimension, i.e., thetransverse dimension normal to the thickness and longitudinaldimensions. To ensure a quick “release”, the shape of the edge 301 a ofthe plucking paddle 300 should generally match this transverse curve.The radius curvature of the transducer 12 in the transverse plane isapproximately 6 inches, and therefore the same radius should be used forthe curve edge 301 a in the transverse plane of the paddle 301.Different sized transducers 12 will have higher or lower transverseradii of curvature, so regardless of the size of the transducer 12, theradius of curvature for the curved edge 301 a in the transverse plane ofthe paddle 301 should substantially match the transverse curvature ofthe transducer 12.

Although both paddle 301 dimensions affect durability, and bothdimensions affect performance, the tip radius has more of an effect onelement 12 performance, while the transverse curve has a greater effecton the element's 12 substrate wear, and therefore is more of aninfluence on its life expectancy. This is because the transverse radiusdetermines how much of the paddle 301 contacts the element 12. A greatercontact area is equates with less wear and longer substrate life, i.e.,durability. As stated above, by manufacturing the paddle 301 fromsufficiently hard or hardened materials, the edge 301 a of the paddle301 can be made with very small radius. The tip 301 a of the pluckingpaddle 301 may be coated with a very hard material with low friction,thereby lowering the plucking resistance. Hardened, low frictionmaterials are useful in increasing the power output of a transducer 12without increasing the required displacement or amount of bending, orallowing the generation of similar electrical energy output with lower“button force”, and increasing wear resistance.

Referring again to FIGS. 11 a-c: In order to return the deflectorassembly 72 to its normal elevated position, the levers 260, 270 and/orplucker assembly 300 are preferably spring loaded. More specifically,one or more springs 310 are located in contact with the deflectorassembly 72, and are placed in compression or tension upon actuation ofthe assembly 72, which springs' 310 restoring force is used to returnthe deflector assembly 72 to its neutral position. As shown in FIGS. 11a-c, in the preferred embodiment of the invention, two springs 310 arelocated within cavities 320 in the plucker housings 290, below the pins304. For simplicity of illustration, the springs 310 are shown as coiledsprings 310, but are preferably leaf springs 310. Upon downwarddeflection of the crossbar 265 and thereby the pivot bar assembly 260and rocker assembly 270, the pins 304 travel down the grooves 308 andcompress the springs 310 in the cavities 320. Upon release of pressurefrom the crossbar 265, the springs 310 restore the pivot bar 260, rockerbars 270 and plucker 300 to their undeflected positions. While thesprings 310 shown are in the housings 290, other placements of thesprings 310 may also be desirable, including, for example: spring(s) 310may be placed beneath the cross bar 265, on either side of the fulcrum268 of the pivot bars 261, 262 or rocker arms 270; one or morerotational or clock springs 310 may be placed on the pins 264 of thepivot bars 261, 262, on the pins 274 of the rocker arms 271, 272, on thepivot bar fulcrums 268, or the rocker arm pin holes 278; springs 310 maybe placed in the groove 308 or recess 320 above or below the plucker barpins 304; one or more springs 310 may be attached to the plucker bar301; and the opposing side of the spring 310 (not attached to thedeflector assembly 72) may be attached to the base plate 70, the pluckerhousing 290, the fulcrum 268 or to another part of the deflectorassembly 72 to restore it to its undeflected position.

Referring now to FIGS. 12 a-e: To facilitate efficient plucking andmaximize vibration of the transducer 12, the plucker assembly ispreferably configured so as to rotate during each actuation and to cockafter each actuation. Specifically, with a triangularly shaped pluckerpaddle 301, any one of the three faces 301 b, 301 c, 301 d of theplucker paddle 301 (having a substantially triangular cross-section) mayengage the edge of the transducer. As the plucker paddle 301 movesdownward and outward from the transducer edge, a rotation mechanism(including a pin 445 and radial ridge 444 as shown in the figures)causes the plucker paddle edge to rotate away from the transducer edge122. As the plucker paddle rotates, it reaches a point where thetransducer edge 122 is released. Since the plucker paddle 301 hasrotated, it also does not interfere with the vibration of the transduceredge. When the downward force is removed from the plucker assembly, thespring loaded plucker paddle 301 is returned upward towards its startingposition, and rotates until the radial ridge 444 contacts a rotationalstop 443, so that the plucker paddle 301 is again is a position toengage the transducer edge.

Referring again to FIGS. 12 a-e: More specifically, the plucker paddle301 is shaped substantially like a triangular prism. In the center ofeach triangular face of the paddle is a pin 304 that travels along thegroove 308 in the plucker housing. Each triangular face of the paddlealso preferably has threes raised ridges 444 thereon extending from thecenter of the triangular face outwardly towards the edges of thetriangular faces adjacent the flat paddle surfaces and most preferablytowards each apex of the triangular faces. The plucker housings eachhave a vertical ridge or pin 443 against which the raised ridge restswhen the plucker paddle is in its maximum position. This maintains thebottom surface of the plucker paddle (opposite the apex bisected by theraised ridge) in an essentially horizontal position above and/or againstthe edge of the transducer 12.

A force applied to the deflector assembly 72 described above causes thepiezoelectric transducer 12 to deform from position 291 to position 292and by virtue of the piezoelectric effect, the deformation of thepiezoelectric element 67 generates an instantaneous voltage between thefaces 12 a and 12 c of the transducer 12, which produces an electricalsignal. Furthermore, when the force is removed from the piezoelectrictransducer 12, i.e., when released by the plucker assembly 300 atposition 292, the transducer 12 oscillates between positions 291 and 292until it gradually returns to its original shape. As the transducer 12oscillates, the ceramic layer 67 strains, becoming alternately morecompressed and less compressed. The polarity of the voltage produced bythe ceramic layer 67 depends on the direction of the strain, andtherefore, the polarity of the voltage generated in compression isopposite to the polarity of the voltage generated in tension. Therefore,as the transducer 12 oscillates, the voltage produced by the ceramicelement 67 oscillates between a positive and negative voltage for aduration of time. The duration of the oscillation, and therefore theduration of the oscillating electrical signal produced, is preferably inthe range of 100-250 milliseconds, depending on the shape, mounting andamount of force applied to the transducer 12. The wave form of theoscillating voltage is illustrated in FIG. 10 a.

Referring now to FIGS. 14 and 16 a-c: FIGS. 14 and 16 a-c show analternate embodiment of a casing with a deflector assembly 72 andcontaining the transducer 12. The base plate 70 forms the base of acasing 200, which encloses the transducer 12. On each side of the casing200 is a wall 201, 202, 203 and 204 which extends perpendicularly fromthe top surface 70 a of the base plate 70. On one end of the casing 200is mounted a deflector assembly 72 or plunger. The plunger has aninterior surface 172 b and an exterior surface 172 a, as well as a freeend 173 and a mounted end 174. More specifically, the plunger 172 ispivotably mounted on one end 174 to a wall 201 of the casing 200. Thefree end 173 of the plunger 172 has a ridge 173 a thereon which engagesa lip 202 a on the opposite wall 202 of the casing. Preferably the freeend 173 of the plunger 172 is spring loaded so that the ridge 173 a isconstantly urged towards the lip 202 a. To this end, there is apreferably a spring 150 held in compression between the top surface 70 aof the base plate 70 and the ridge 173 a or interior surface of theplunger 172 b. This provides for device wherein an transducer 12 mountedon a base plate 70 is contained within a casing 200 formed by the baseplate 70 and four walls 201, 202, 203 and 204 as well as a plunger 172pivotably mounted opposite the base plate 70 on a wall 201 of the casing200. Because the plunger is pivotably mounted, placing pressure (in thedirection of arrow 180 on the on the exterior surface 172 a of theplunger 172 makes it pivot about the hinge 175 toward the top surface 70a of the base plate 70. Because the plunger is pivotably mounted andspring loaded, releasing pressure from the on the exterior surface 172 aof the plunger 172 makes it pivot about the hinge 175 away the topsurface of the base plate 70 until the ridge 173 a catches on the lip202 a.

Within the casing 200 is a mounted quick release mechanism 180comprising a spring loaded rocker arm 185 on the interior surface 172 bof the plunger 172 which works in conjunction with a release pin 186mounted on the top surface 70 of the base plate 70. The quick releasemechanism 180 is designed to deflect and then quickly release the freeend 122 of the transducer 12 in order to allow it to vibrate betweenpositions 291 and 292. The quick release mechanism 180 is also designednot to interfere with the vibration of the transducer 12 as well as toreturn to a neutral position for follow-on deflections of the transducer12.

Referring to FIGS. 16 a-c: The rocker arm 185 is pivotably attached tothe interior surface 172 b of the plunger 172 above the free end 122 ofthe transducer 12. More specifically, the rocker arm 185 is pivotablyattached in such a way that it has a neutral position from which it maypivot away from the clamped end 121 of the transducer 12, but will notpivot towards the clamped end 121 of the transducer 12 from that neutralposition. In other words a rotational stop 183 forms part of the quickrelease mechanism 180 and its placement prevents the rocker arm frompivoting beyond the neutral position at the stop 183. The rocker arm 185is preferably spring loaded in order to keep the rocker arm 185 in itsneutral position when not being deflected. To this end a spring 187 incompression is placed on the side of the rocker arm 185 opposite thestop 183, between the rocker arm 185 and a spring stop 188.

Inside the casing 200 is also a release pin 186 which is located on thetop surface 70 a of the base plate 70. The release pin 186 is located ina position just beyond the free end 122 of the transducer 12 in itsdeflected position, but not beyond the rocker arm 185. In other words,when the plunger 172 is depressed toward the release pin 186, depressingwith it the transducer 12 from position 291 to position 292, the releasepin 186 will contact the rocker arm 185 but not the transducer 12. Asthe rocker arm 185 (and transducer 12) are depressed further, therelease pin 186 pushes the rocker arm 185 away, making the rocker arm185 pivot away from the clamped end 121 of the transducer 12. The rockerarm 185 pivots until the edge 122 of the transducer 12 is no longer heldby the rocker arm 185 in position 292, at which point the edge 122 ofthe transducer 12 is released and springs back to its undeformed state,thereby oscillating between positions 291 and 292.

When pressure from the plunger 172 is released, the plunger 172 returnsto its undeflected position (with the ridge 173 a against the lip 202 a)by virtue of the restoring force of the spring 150. Also when thepressure from the plunger 172 is released, and the plunger 172 returnsto its undeflected position, the rocker arm 185 also returns to itsundeflected position (above the transducer 12 against the stop 183) byvirtue of the restoring force of the spring 187. Lastly, the transducer12 also returns to its undeflected state in position 291 after itsoscillations between positions 291 and 292 have ceased.

Referring now to FIGS. 15 and 17 a-d: FIGS. 15 and 15 a-d show analternate embodiment of a deflector assembly 72 mounted to a casing 200that contains the transducer 12. The base plate 70 forms the base of acasing 200, which encloses the transducer 12. On each side of the casing200 is a wall 201, 202, 203 and 204 which extends perpendicularly fromthe top surface 70 a of the base plate 70. Attached to the top of thewalls of the casing 200 (opposite the base plate 70) is a face plate 220to which is mounted a slide mechanism 230 that acts as a deflectorassembly 72. The face plate 220 has an interior surface 220 a and anexterior surface 220 b and a channel 240 extending through substantiallythe center of the face plate 220. The channel 240 has a first end 241and a second end 242 and extends substantially linearly along an axis Lperpendicular to the first and second walls 201 and 202 of the casing200. In other words, the first end 241 of the channel 240 through theface plate 220 is in proximity to the first wall 201 of the casing 200and the second end 242 of the channel 240 through the face plate 220 isin proximity to the second wall 202 of the casing 200. The second end ofthe channel 240 preferably extends further towards the second wall 202of the casing than does the free end 122 of the transducer 12.

The channel 240 is adapted to slidably retain a spring loaded paddle250. Preferably, the paddle has first and second ends 251 and 252respectively and a central pin 255. The channel in the face plate 220allows the paddle to extend through the face plate 220, while alsoslidably retaining the central pin 255 in the channel 240. Morespecifically, the paddle 250 extends through the face plate 220 by meansof the channel 240, along which the paddle may be slid in a directionparallel to the channels' axis L, i.e., from the clamped end 121 to thefree end 122 of the transducer 12 and back. The first end 251 of thepaddle 250 is located above the exterior surface 220 b of the face plate220 and the second end 252 of the paddle 250 is located within thecasing 200 above the transducer 12. The paddle 250 is retained in thedescribed position be means of the pin 255 which is retained in thechannel 240. Thus, the width of the channel 240 at the exterior surface220 b is sufficient for the paddle upper portion 251 to pass through, asis the width of the channel 240 at the interior surface 220 a issufficient for the paddle lower portion 252 to pass through. The widthand height of the channel 240 within the face plate 220 (between theinterior and exterior surfaces 220 a and 220 b) is sufficient toaccommodate the width and height of the central pin 255, which is widerthan the width of the paddle upper and lower portions 251 and 252.

The first end 251 of the paddle 250 preferably extends a distance abovethe exterior surface 220 b of the face plate 220 enough to be graspedmanually. The second end 252 of the paddle 250 preferably extends intothe casing 200 a distance above the transducer 12 such that the paddle250 does not contact the clamping member 75 and/or clamped end 121 ofthe transducer 12, but also far enough that it may contact and deflectthe free end 122 of the transducer 12. The paddle 250 is also preferablyhinged at the second end 252 (within the casing 200 or the channel 240at or in proximity to the central pin 255) in a manner that allows thesecond end 252 to pivot about the hinge or central pin 255 whentravelling in one direction but not the other. Preferably, the secondend 252 of the paddle 250 is hinged in a way that it may pivot when thepaddle 250 is travelling toward the first wall 201 of the casing 200 butnot pivot when travelling towards the second wall 202 of the casing 200.

Preferably the paddle 250 is also spring loaded so that the paddle isconstantly urged along the channel 240 towards the first wall 201 of thecasing 200. To that end, there is a spring 260 held between the paddleand the first 201 or second wall 202 of the casing 200 or mostpreferably the spring 260 held between the paddle 250 and the first orsecond end 241 or 242 of the channel 240. In order to urge the paddletoward the first wall 201 the spring 260 is either held in tensionbetween the paddle 250 and the first end 241 of the channel 240, or mostpreferably the spring 260 is held in compression between the paddle 250and the second end 242 of the channel 240.

This provides for device wherein an transducer 12 mounted on a baseplate 70 is contained within a casing 200 formed by the base plate 70,four walls 201, 202, 203 and 204 and a face plate opposite the baseplate 70. Because the paddle 250 is slidably mounted, placing pressure(in the direction of arrow 281 on the on the 251 first end of the paddlemakes it slide along the channel 240 toward the second wall 202 of thecasing 200. Because the paddle 250 is slidably mounted and springloaded, releasing pressure from the paddle 250 makes it return along thechannel 240 toward the first wall 201 of the casing 200 until it comesto rest against the first end 241 of the channel 240.

Referring to FIGS. 16 a-d: The paddle upper portion 251 is pivotablyattached to the paddle lower portion 252 below the interior surface 220a of the face plate 220 (within the casing 200) above the transducer 12.More specifically, the paddle lower portion 252 is pivotably attached insuch a way that it has a neutral position from which it may pivot awayfrom the clamped end 121 of the transducer 12, but will not pivottowards the clamped end 121 of the transducer 12 from that neutralposition. In other words the shape of the paddle 250 prevents the lowerportion 252 from pivoting beyond the neutral position.

In operation, when the paddle 250 is moved (in the direction of arrow281) toward the second end 242 of the channel 240, the paddle lowerportion 252 contacts concave face 12 c of the transducer 12 andcommences to deflect the transducer 12 free end 122 (away from position291). As the paddle 250 continues to move in the direction of arrow 281,the paddle lower portion 252 depresses the free end 122 of thetransducer 12 to its maximum deflection at position 292 when the freeend 122 is directly beneath the paddle lower portion 252. When thepaddle moves further from this point in the direction of arrow 281, thefree end 122 of the transducer 12 is abruptly released from the applieddeflection of the paddle lower portion 252. Upon release, the edge 122of the transducer 12 springs back to its undeformed state at position291, thereby oscillating between positions 291 and 292. Upon release ofpressure (in the direction of arrow 281) from the paddle 250, the paddlethen travels in the direction of arrow 282, by virtue of the restoringforce of the spring 260. As the paddle 250 returns towards itsundeflected position (towards the first end 241 of the channel 240), thefree end 122 of the transducer 12 in position 291 applies pressureagainst the lower portion 252 of the paddle 250. In response to thepressure being applied to the paddle lower portion opposite thedirection of travel of the upper portion 251, the lower portion 252pivots about the hinged central pin 255 of the paddle. After the paddlelower portion 252 has traveled in the direction of arrow 282 beyond thefree end 122 of the transducer 12, the lower portion 252 returns to itsundeflected (unbent) state. The pivoting of the paddle lower portion 252allows the paddle 250 to return to its neutral undeflected position atthe first end 241 of the channel 240.

When the end 122 of the transducer 12 is deflected and then released(either manually or using a deflector assembly 72 such as in FIGS. 6-7,or 11-16), the end 122 of the transducer 12, much like a diving board,oscillates back and forth between positions 291 and 292. This is becausethe substrate and prestress layer 64 and 68 to which the ceramic 67 isbonded exert a compressive force on the ceramic 67 thereby providing arestoring force. Therefore, the transducer 12 has a coefficient ofelasticity or spring constant that causes the transducer 12 to return toits undeformed neutral state at position 291. The oscillation of thetransducer 12 has the waveform of a damped harmonic oscillation, as isillustrated in FIG. 10 a. In other words, the amplitude of theoscillation of the free end 122 of the transducer 12 is at its maximumimmediately following (within a few oscillations after) the release ofthe mechanical impulse from the free end 122 of the transducer 12. Asthe transducer 12 continues to vibrate, the amplitude graduallydecreases over time (approximately exponentially) until the transducer12 is at rest in its neutral position 291, as shown in FIG. 10 a.

The applied force, whether by manual or other mechanical deflectionmeans 72 causes the piezoelectric transducer 12 to deform and by virtueof the piezoelectric effect, the deformation of the piezoelectricelement 67 generates an instantaneous voltage between the faces 12 a and12 c of the transducer 12, which produces an electrical signal.Furthermore, when the force is removed from the piezoelectric transducer12, the transducer 12 oscillates between positions 291 and 292 until itgradually returns to its original shape. As the transducer 12oscillates, the ceramic layer 67 strains, becoming alternately morecompressed and less compressed. The polarity of the voltage produced bythe ceramic layer 67 depends on the direction of the strain, andtherefore, the polarity of the voltage generated in compression isopposite to the polarity of the voltage generated in tension. Therefore,as the transducer 12 oscillates, the voltage produced by the ceramicelement 67 oscillates between a positive and negative voltage for aduration of time. The duration of the oscillation, and therefore theduration of the oscillating electrical signal produced, is preferably inthe range of 100-500 milliseconds, depending on the shape, mounting andamount of force and number of plucks applied to the edge of thetransducer 12.

The electrical signal generated by the transducer 12 is applied todownstream circuit elements via wires 14, and conductive foil, solder orconductive adhesive connected to the transducer 12. More specifically, afirst wire 14 is connected to the electrode 90 which extends into therecess 80 and contacts the electrode 68 on the convex face 12 a of thetransducer 12 or to a foil adhered to the lower face 12 a of thetransducer 12. Preferably the wire 14 is attached to a conductive foil(not shown) adhered to the face 12 a of the transducer 12 situated abovethe recess 80 and compliant layer 85. Alternately, the wire 14 isconnected to the electrode 90 outside of the recess close to the end ofthe base plate 70 opposite the end having the clamping member 75. Asecond wire 14 is connected directly to the first prestress layer 64,i.e., the substrate 64 which acts as an electrode on the concave face 12c of the transducer 12.

In each embodiment of a self powered RF signal generator, the transducer12, base 70, 200 and associated transmission circuitry are enclosed in acase, such as described above having a base 200, and wall 2021, 202, 203and 204, as well as a top face. The case may be made of a variety ofmaterials including plastics and metal or combinations thereof. Mostpreferably, the outer case (top face and wall comprise plastic. It hasbeen discovered that the character of the RF signal radiated from theantenna 60 in the transmitter circuit 126 varies with the placement ofthe antenna in relation to parts of the casing as well as otherobstructions placed in proximity to the antenna. To this end it ispreferred that the antenna 60 be fixedly mounted to the base 200, and/orwalls 201, 202, 203 and 204 of the casing. Most preferably, the antennais affixed to the casing in a channel in the base 200, and/or wall 201,202, 203 and 204 or otherwise fixed thereto. Furthermore, it ispreferable that at least a portion of the base be made of metal. Objects(i.e., in walls) to which the base 200 is mounted may cause interferencewith the signal radiated from the antenna 60. Therefore a portion of thebase 20 is preferred to be metallic in order to shield the antenna fromany interference.

Electromagnetic Generator

Referring to FIGS. 17 and 18: In an alternate embodiment of theinvention, the electromechanical energy is provided using a magneticbased microgenerator, rather than a piezoelectric device. The actuationmeans for generating the electrical signal comprises a magnet and aseries of coils, which generate an electrical signal in response torelative motion between the magnet and the coils. A rotary or linear DCmotor may be used as a generator in a manner similar to that used in anelectric car to recharge the batteries during regenerative braking, inorder to generate electrical energy for actuating a latching/relaymechanism and/or powering an RF generation circuit. The magneticallybased microgenerator may be used rotary, having a rotor and stator togenerate an electric impulse in wire coils due to relative motionbetween the magnetic field and the coil. Alternatively themicrogenerator may be linearly operated. Preferably a small rare earthmagnet, which has a high magnetic field per unit volume, is moved alonga line in relation to several wire coils to generate the electricalimpulse.

Referring again to FIGS. 17 and 18: In the preferred embodiments of theelectromagnetic generator 98 or 99, mechanical or manual actuationmeans, such as a linear switch 103 or rotary switch 203 is coupled toone or more magnets 105 or 205 a-c respectively, and more preferably arare earth magnet. Rare earth magnets are preferred because they havehigher magnetic fields than typical permanent magnets. A small rareearth magnet may be used so that the electromagnetic generator may bemade more compact.

The electromagnetic generator 98 or 99 also comprises a series of wirecoils 106 or 206. More specifically, for a magnet 105 coupled to alinear switch 103, a series of small wire coils 106 are arranged along asubstrate 104 in close proximity to and substantially parallel to thelongitudinal axis along which the rare earth magnet 105 moves inresponse to actuation of the linear switch 103. Alternately, the coilscomprise a series of coils 206 arranged on the interior of a circularsubstrate 204, i.e., around a central axis about which the magnets 205a, 205 b and 205 c rotates in response to actuation of a rotary switch203. There may be as few as one coil, but preferably at least threecoils are located along the axis relative to which the magnet moves.More specifically, 6 or more coils are preferably evenly spaced alongthe axis of motion of the magnet, which for a linear actuator 98 is atleast three times the length of the magnet.

In operation, when the manual or mechanical actuation of the linearswitch 103, the attached magnet 105 moves along longitudinal axis fromposition 111 to position 112. As the magnet 105 passes a coil 106, thechanging magnetic field creates an electric field in the coil 106. Thecurrent flows from ground (not shown) through the coil 106 and into awire 107 connected to a conductor 14. This happens at each coil 106 sothat as the magnet 105 passes the series of coils 106 an electric fieldis generated in each coil 106 and is summed at conductor 14. In a likemanner, when the rotary switch 203 in the embodiment of FIG. 11 isrotated, the magnet(s) 205 a-c move in relation to the coils 206attached to the periphery of the casing 204 of the electromagnetic motor99, and generate an electric field in a like manner.

Switch Initiation System

Referring to FIGS. 6 and 7: The pulse of electrical energy istransmitted from the transducer or generator 12, 98 or 99 via theelectrical wires 14 connected to each of the transducer 12 to a switchor relay 90. The pulse of electrical energy is of sufficient magnitudeto cause the switch/relay 90 to toggle from one position to another.Alternatively and preferably, the electrical pulse is first transmittedthrough a pulse modification circuit 10 in order to modify thecharacter, i.e, current, voltage, frequency and/or pulse width of theelectrical signal.

Referring to FIGS. 20-25, the transducer 12 is connected to circuitcomponents downstream in order to generate an RF signal for actuation ofa switch initiator. These circuit components include a rectifier 31, avoltage regulator U2, an encoder 40 (preferably comprising a peripheralinterface controller (PIC) chip) as well as an RF generator 50 andantenna 60. FIG. 10 b shows the waveform of the electrical signal ofFIG. 10 a after it has been rectified. FIG. 10 c shows the waveform ofthe rectified electrical signal of FIG. 10 b after it has been regulatedto a substantially uniform voltage, preferably 3.3 VDC.

Referring now to FIG. 22: The transducer 12 is first connected to arectifier 31. Preferably the rectifier 31 comprises a bridge rectifier31 comprising four diodes D1, D2, D3 and D4 arranged to only allowpositive voltages to pass. The first two diodes D1 and D2 are connectedin series, i.e., the anode of D1 connected to the cathode of D2. Thesecond two diodes D3 and D4 are connected in series, i.e., the anode ofD3 connected to the cathode of D4. The anodes of diodes D2 and D4 areconnected, and the cathodes of diodes D1 and D3 are connected, therebyforming a bridge rectifier. The rectifier is positively biased towardthe D2-D4 junction and negatively biased toward the D1-D3 junction. Oneof the wires 14 of the transducer 12 is electrically connected betweenthe junction of diodes D1 and D2, whereas the other wire 14 (connectedto the opposite face of the transducer 12) is connected to the junctionof diodes D3 and D4. The junction of diodes D1 and D3 are connected toground. A capacitor C11 is preferably connected on one side to the D2-D4junction and on the other side of the capacitor C11 to the D1-D3junction in order to isolate the voltages at each side of the rectifierfrom each other. Therefore, any negative voltages applied to the D1-D2junction or the D3-D4 junction will pass through diodes D1 or D3respectively to ground. Positive voltages applied to the D1-D2 junctionor the D3-D4 junction will pass through diodes D2 or D4 respectively tothe D2-D4 junction. The rectified waveform is shown in FIG. 10 b.

The circuit also comprises a voltage regulator U2, which controlsmagnitude of the input electrical signal downstream of the rectifier 31.The rectifier 31 is electrically connected to a voltage regulator U2with the D2-D4 junction connected to the Vin pin of the voltageregulator U2 and with the D1-D3 junction connected to ground and theground pin of the voltage regulator U2. The voltage regulator U2comprises for example a LT1121 chip voltage regulator U2 with a 3.3volts DC output. The output voltage waveform is shown in FIG. 10 c andcomprises a substantially uniform voltage signal of 3.3 volts having aduration of approximately 100-250 milliseconds, depending on the loadapplied to the transducer 12. The regulated waveform is shown in FIG. 10b. The output voltage signal from the voltage regulator (at the Voutpin) may then be transmitted via another conductor to the relay switch290, in order to change the position of a relay switch 290 from oneposition to another. Preferably however, the output voltage is connectedthrough an encoder 40 to an RF generation section 50 of the circuit.

Referring again to FIGS. 20 and 22: The output of the voltage regulatorU2 is preferably used to power an encoder 40 or tone generatorcomprising a peripheral interface controller (PIC) microcontroller thatgenerates a pulsed tone. This pulsed tone modulates an RF generatorsection 50 which radiates an RF signal using a tuned loop antenna 60.The signal radiated by the loop antenna is intercepted by an RF receiver270 and a decoder 280 which generates a relay pulse to activate therelay 290.

The output of the voltage regulator U2 is connected to a PICmicrocontroller, which acts as an encoder 40 for the electrical outputsignal of the regulator U2. More specifically, the output conductor forthe output voltage signal (nominally 3.3 volts) is connected to theinput pin of the programmable encoder 40. Types of register-based PICmicrocontrollers include the eight-pin PIC12C5XX and PIC12C67x, baselinePIC16C5X, midrange PIC16CXX and the high-end PIC17CXX/PIC18CXX. Thesecontrollers employ a modified Harvard, RISC architecture that supportvarious-width instruction words. The datapaths are 8 bits wide, and theinstruction widths are 12 bits wide for the PIC16C5X/PIC12C5XX, 14 bitswide for the PIC12C67X/PIC16CXX, and 16 bits wide for thePIC17CXX/PIC18CXX. PICMICROS are available with one-time programmableEPROM, flash and mask ROM. The PIC17CXX/PIC18CXX support externalmemory. The encoder 40 comprises for example a PIC model 12C671. ThePIC12C6XX products feature a 14-bit instruction set, small packagefootprints, low operating voltage of 2.5 volts, interrupts handling,internal oscillator, on-board EEPROM data memory and a deeper stack. ThePIC12C671 is a CMOS microcontroller programmable with 35 single wordinstructions and contains 1024×14 words of program memory, and 128 bytesof user RAM with 10 MHz maximum speed. The PIC12C671 features an 8-leveldeep hardware stack, 2 digital timers (8-bit TMRO and a Watchdog timer),and a four-channel, 8-bit A/D converter.

The output of the PIC may include square, sine or saw waves or any of avariety of other programmable waveforms. Typically, the output of theencoder 40 is a series of binary square waveforms (pulses) oscillatingbetween 0 and a positive voltage, preferably +3.3 VDC. The duration ofeach pulse (pulse width) is determined by the programming of the encoder40 and the duration of the complete waveform is determined by theduration of output voltage pulse of the voltage regulator U2. Acapacitor C5 is preferably be connected on one end to the output of thevoltage regulator U2, and on the other end to ground to act as a filterbetween the voltage regulator U2 and the encoder 40.

Thus, the use of an IC as a tone generator or encoder 40 allows theencoder 40 to be programmed with a variety of values. The encoder 40 iscapable of generating one of many unique encoded signals by simplyvarying the programming for the output of the encoder 40. Morespecifically, the encoder 40 can generate one of a billion or morepossible codes. It is also possible and desirable to have more than oneencoder 40 included in the circuit in order to generate more than onecode from one transducer 12 or transmitter. Alternately, any combinationof multiple transducers and multiple pulse modification subcircuits maybe used together to generate a variety of unique encoded signals.Alternately the encoder 40 may comprise one or more inverters forming aseries circuit with a resistor and capacitor, the output of which is asquare wave having a frequency determined by the RC constant of theencoder 40.

The DC output of the voltage regulator U2 and the coded output of theencoder 40 are connected to an RF generator 50. A capacitor C6 maypreferably be connected on one end to the output of the encoder 40, andon the other end to ground to act as a filter between the encoder 40 andthe RF generator 50. The RF generator 50 consists of tank circuitconnected to the encoder 40 and voltage regulator U2 through both abipolar junction transistor (BJT) Q1 and an RF choke. More specifically,the tank circuit consists of a resonant circuit comprising an inductorL2 and a capacitor C8 connected to each other at each of theirrespective ends (in parallel). Either the capacitor C8 or the inductorL2 or both may be tunable in order to adjust the frequency of the tankcircuit. An inductor L1 acts as an RF choke, with one end of theinductor L1 connected to the output of the voltage regulator U2 and theopposite end of the inductor L1 connected to a first junction of theL2-C8 tank circuit. Preferably, the RF choke inductor L1 is an inductorwith a diameter of approximately 0.125 inches and turns on the order ofthirty and is connected on a loop of the tank circuit inductor L2. Thesecond and opposite junction of the L2-C8 tank circuit is connected tothe collector of BJT Q1. The base of the BJT Q1 is also connectedthrough resistor R2 to the output side of the encoder 40. A capacitor C7is connected to the base of a BJT Q1 and to the first junction of thetank circuit. Another capacitor C9 is connected in parallel with thecollector and emitter of the BJT Q1. This capacitor C9 improves thefeedback characteristics of the tank circuit. The emitter of the BJT Q1is connected through a resistor R3 to ground. The emitter of the BJT Q1is also connected to ground through capacitor C10 which is in parallelwith the resistor R3. The capacitor C10 in parallel with the resistor R3provides a more stable conduction path from the emitter at highfrequencies.

The RF generator 50 works in conjunction with a tuned loop antenna 60.In the preferred embodiment, the inductor L2 of the tank circuit servesas the loop antenna 60. More preferably, the inductor/loop antenna L2comprises a single rectangular loop of copper wire which may have anadditional smaller loop or jumper (not shown) connected to therectangular loop L2. Adjustment of the shape and angle of the smallerloop relative to the rectangular loop L2 is used to increase or decreasethe apparent diameter of the inductor L2 and thus tunes the RFtransmission frequency of the RF generator 50. In an alternateembodiment, a separate tuned antenna may be connected to the secondjunction of the tank circuit.

In operation: The positive voltage output from the voltage regulator U2is connected the encoder 40 and the RF choke inductor L1. The voltagedrives the encoder 40 to generate a coded square wave output, which isconnected to the base of the BJT Q1 through resistor R2. When the codedsquare wave voltage is zero, the base of the BJT Q1 remainsde-energized, and current does not flow through the inductor L1. Whenthe coded square wave voltage is positive, the base of the BJT Q1 isenergized through resistor R2. With the base of the BJT Q1 energized,current is allowed to flow across the base from the collector to theemitter and current is also allowed to flow across the inductor L1. Whenthe square wave returns to a zero voltage, the base of the BJT Q1 isagain de-energized.

When current flows across the choke inductor L1, the tank circuitcapacitor C8 charges. Once the tank circuit capacitor C8 is charged, thetank circuit begins to resonate at the frequency determined by thecircuit's LC constant. For example, a tank circuit having a 7 picofaradcapacitor and an inductor L2 having a single rectangular loop measuring0.7 inch by 0.3 inch, the resonant frequency of the tank circuit is 310MHz. The choke inductor L1 prevents RF leakage into upstream componentsof the circuit (the PIC) because changing the magnetic field of thechoke inductor L1 produces an electric field opposing upstream currentflow from the tank circuit. To produce an RF signal, charges have tooscillate with frequencies in the RF range. Thus, the chargesoscillating in the tank circuit inductor/tuned loop antenna L2 producean RF signal of preferably 310 MHz. As the square wave output of theinverter turns the BJT Q1 on and off, the signal generated from the loopantenna 60 comprises a pulsed RF signal having a duration of 100-250milliseconds and a pulse width determined by the encoder 40, (typicallyof the order of 0.1 to 5.0 milliseconds thus producing 20 to 2500 pulsesat an RF frequency of approximately 310 MHz. The RF generator section 50is tunable to multiple frequencies. Therefore, not only is thetransmitter capable of a great number of unique codes, it is alsocapable of generating each of these codes at a different frequency,which greatly increases the number of possible combinations of uniquefrequency-code signals.

The RF generator 50 and antenna 60 work in conjunction with an RFreceiver 270. More specifically, an RF receiver 270 in proximity to theRF transmitter 126 (within 300 feet) can receive the pulsed RF signaltransmitted by the RF generator 50. The RF receiver 270 comprises areceiving antenna 270 for intercepting the pulsed RF signal (tone). Thetone generates a pulsed electrical signal in the receiving antenna 270that is input to a microprocessor chip that acts as a decoder 280. Thedecoder 280 filters out all signals except for the RF signal it isprogrammed to receive, e.g., the signal generated by the RF generator50. An external power source is also connected to the microprocessorchip/decoder 280. In response to the intercepted tone from the RFgenerator 50, the decoder chip produces a pulsed electrical signal. Theexternal power source connected to the decoder 280 augments the pulsedvoltage output signal developed by the chip. This augmented (e.g., 120VAC) voltage pulse is then applied to a conventional relay 290 forchanging the position of a switch within the relay. Changing the relayswitch position is then used to turn an electrical device with a bipolarswitch on or off, or toggle between the several positions of a multipleposition switch. Zero voltage switching elements may be added to ensurethe relay 290 activates only once for each depression and recovery cycleof the flextensional transducer element 12.

Switch Initiator System with Trainable Receiver

Several different RF transmitters may be used that generate differenttones for controlling relays that are tuned to receive that tone. Inanother embodiment, digitized RF signals may be coded and programmable(as with a garage door opener) to only activate a relay that is codedwith that digitized RF signal. In other words, the RF transmitter iscapable of generating at least one tone, but is preferably capable ofgenerating multiple tones. Most preferably, each transmitter isprogrammed with one or more unique coded signals. This is easily done,since programmable ICs for generating the tone can have over 230possible unique signal codes which is the equivalent of over 1 billioncodes. Most preferably the invention comprises a system of multipletransmitters and one or more receivers for actuating building lights,appliances, security systems and the like. In this system for remotecontrol of these devices, an extremely large number of codes areavailable for the transmitters for operating the lights, appliancesand/or systems and each transmitter has at least one unique, permanentand nonuser changeable code. The receiver and controller module at thelights, appliances and/or systems is capable of storing and rememberinga number of different codes corresponding to different transmitters suchthat the controller can be programmed so as to actuated by more than onetransmitted code, thus allowing two or more transmitters to actuate thesame light, appliance and/or system.

The remote control system includes a receiver/controller for learning aunique code of a remote transmitter to cause the performance of afunction associated with the system, light or appliance with which thereceiver/controller module is associated. The remote control system isadvantageously used, in one embodiment, for interior or exteriorlighting, household appliances or security system. Preferably, aplurality of transmitters is provided wherein each transmitter has atleast one unique and permanent non-user changeable code and wherein thereceiver can be placed into a program mode wherein it will receive andstore two or more codes corresponding to two or more differenttransmitters. The number of codes which can be stored in transmitterscan be extremely high as, for example, greater than one billion codes.The receiver has a decoder module therein which is capable of learningmany different transmitted codes, which eliminates code switches in thereceiver and also provides for multiple transmitters for actuating thelight or appliance. Thus, the invention makes it possible to eliminatethe requirements for code selection switches in the transmitters andreceivers.

Referring to FIGS. 20-21: The receiver module 101 includes a suitableantenna 270 for receiving radio frequency transmissions from one or moretransmitters 126 and 128 and supplies an input to a decoder 280 whichprovides an output to a microprocessor unit 244. The microprocessor unit244 is connected to a relay device 290 or controller which switches thelight or appliance between one of two or more operation modes, i.e., on,off, dim, speed control, heat, cool or some other mode of operation. Aswitch 222 is mounted on a switch unit 219 connected to the receiver andalso to the microprocessor 244. The switch 222 is a two position switchthat can be moved between the “operate” and “program” positions toestablish operate and program modes.

In the invention, each transmitter, such as transmitters 126 and 128,has at least one unique code which is determined by the tonegenerator/encoder 40 contained in the transmitter. The receiver unit 101is able to memorize and store a number of different transmitter codeswhich eliminates the need of coding switches in either the transmitteror receiver which are used in the prior art. This also eliminates therequirement that the user match the transmitter and receiver codeswitches. Preferably, the receiver 101 is capable of receiving manytransmitted codes, up to the available amount of memory locations 147 inthe microprocessor 144, for example one hundred or more codes.

When the controller 290 for the light or appliance is initiallyinstalled, the switch 222 is moved to the program mode and the firsttransmitter 126 is energized so that the unique code of the transmitter126 is transmitted. This is received by the receiver module 101 havingan antenna 270 and decoded by the decoder 280 and supplied to themicroprocessor unit 244. The code of the transmitter 126 is thensupplied to the memory address storage 247 and stored therein. Then ifthe switch 222 is moved to the operate mode and the transmitter 126energized, the receiver 270, decoder 280 and the microprocessor 244 willcompare the received code with the code of the transmitter 126 stored inthe first memory location in the memory address storage 247 and sincethe stored memory address for the transmitter 126 coincides with thetransmitted code of the transmitter 126 the microprocessor 244 willenergize the controller mechanism 290 for the light or appliance toenergize de-energize or otherwise operate the device.

In order to store the code of the second transmitter 128 the switch 222is moved again to the program mode and the transmitter 128 is energized.This causes the receiver 270 and decoder 280 to decode the transmittedsignal and supply it to the microprocessor 244 which then supplies thecoded signal of the transmitter 128 to the memory address storage 147where it is stored in a second address storage location. Then the switch222 is moved to the operate position and when either of the transmitters126 and 128 are energized, the receiver 270 decoder 280 andmicroprocessor 244 will energize the controller mechanism 290 for thelight or appliance to energize de-energize or otherwise operate thedevice. Alternately, the signal from the first transmitter 126 andsecond transmitter 128 may cause separate and distinct actions to beperformed by the controller mechanism 290.

Thus, the codes of the transmitters 126 and 128 are transmitted andstored in the memory address storage 247 during the program mode afterwhich the system, light or appliance controller 290 will respond toeither or both of the transmitters 126 and 128. Any desired number oftransmitters can be programmed to operate the system, light or applianceup to the available memory locations in the memory address storage 247.

This invention eliminates the requirement that binary switches be set inthe transmitter or receiver as is done in systems of the prior art. Theinvention also allows a controller to respond to a number of differenttransmitters because the specific codes of a number of the transmittersare stored and retained in the memory address storage 247 of thereceiver module 101.

In yet another more specific embodiment of the invention, eachtransmitter 126 or 128 contains two or more unique codes for controllinga system, light or appliance. One code corresponds in the microprocessorto the “on” position and another code corresponds in the microprocessor244 to the “off” position of the controller 290. Alternately, the codesmay correspond to “more” or “less” respectively in order to raise orlower the volume of a sound device or to dim or undim lighting forexample. Lastly, the unique codes in a transmitter 126 or 128 maycomprise four codes which the microprocessor interprets as “on”, “off”,“more” and “less” positions of the controller 290, depending on thedesired setup of the switches. Alternatively, a transmitter 126 or 128may only have two codes, but the microprocessor 244 interprets repeatedpushes of “on” or “off” signals respectively to be interpreted as dim upand dim down respectively.

Referring to FIGS. 25 and 12-14: The encoder 40 may further beprogrammable to generate a different code, dependent upon which of themultiple input connections is energized. The DC output of the voltageregulator U2 and the coded output of the encoder are connected to an RFgenerator 50 via one or more membrane switches 321, 322 on thefaceplate/deflector 72. The design and construction of two differentmembrane switches is shown in FIGS. 26-27. When a membrane switch 321,322 is pressed, it creates electrical contact between the output of thevoltage regulator U2 and one of the input pins to the PIC encoder 40.The encoder 40 output signal (code) is dependent upon which input pinhas the voltage applied thereto. That is to say, the output signal orcode is dependent upon and different for each pin energized by therespective membrane switch that is pressed/closed. For example, when themechanical deflector is pressed (but not a membrane switch 321 or 322),the encoder is energized and sends a default code to the RF transmitter.However, when a membrane switch 321 depressed, it creates electricalcontact from the voltage regulator U2 to a different pin of the encoder40, thus changing the output of the encoder to a different code from thedefault code. Likewise, when a different witch 322 depressed, it createselectrical contact from the voltage regulator U2 to a yet another pin ofthe encoder 40, thus changing the output of the encoder to a thirddifferent code from the default code and second codes. These codes cancorrespond to a variety of functions for electrical appliances thatreceive the transmitted code such as a light switch, a dimmer, anelectrical appliance power source, a security system, a motorcontroller, a solenoid, a piezoelectric transducer and a latching pinfor a locking system. Exemplary functions that are associated with themembrane switches and concomitant coded outputs of the encoder 40include “TOGGLE”’, “ON”, “OFF”, “DIM”, “UNDIM/BRIGHTEN”, “LOCK”,“UNLOCK”, “SPEED UP”, “SLOW DOWN”, “TEMPERATURE UP”, “TEMPERATURE DOWN”,“ACTIVATE”, “RESET” or the like command functions for electricalappliances connected to the receiver.

Basic membrane switch contact designs are shown without an over layer inFIGS. 17 and 18. The shorting contact 325 of FIG. 18 on the right isnormally attached to a resilient material that holds it off the surfaceof the interdigitated fingers 326 and 327 when it is not pressed down.The shorting contact 325 of FIG. 17 is a metallic dome situated aboveconcentric electrical traces 328 and 329, and when the dome 325 ispressed contacts at least the outer circular trace 328, and when fullydepressed contacts bother the inner 329 and outer 328 traces.

The contact area design is another important and interesting element ofa membrane switch. Contact finish can vary. Gold, nickel, silver andeven graphite have been used. The layout will vary with the type ofcontact used. For example, for a shorting contact, interdigitatedfingers are often used. However, when a metal dome contact is employed,a central contact with a surrounding ring is frequently seen.

In another embodiment of the invention, receiver modules 101 may betrained to accept the transmitter code(s) in one-step. Basically, thememory 147 in the microprocessor 244 of the receiver modules 101 willhave “slots” where codes can be stored. For instance one slot may be forall of the codes that the memory 147 accepts to be turned on, anotherslot for all the off codes, another all the 30% dimmed codes, etc.

Each transmitter 126 has a certain set of codes. For example onetransmitter may have just one code, a “toggle” code, wherein thereceiver module 101 knows only to reverse its current state, if it's on,turn off, and if it's off, turn on. Alternatively, a transmitter 126 mayhave many codes for the complex control of appliances. Each of thesecodes is “unique”. The transmitter 126 sends out its code set in a wayin which the receiver 101 knows in which slots to put each code. Also,with the increased and longer electrical signal that can be generated inthe transmitter 126, a single transmission of a code set is achievableeven with mechanically produced voltage. As a back-up, if this is nottrue, and if wireless transmission uses up more electricity than we haveavailable, some sort of temporary wired connection (upper not shown)between each transmitter and receiver target is possible. Although thedisclosed embodiment shows manual or mechanical interaction with thetransmitter and receiver to train the receiver, it is yet desirable toput the receiver in reprogram mode with a wireless transmission, forexample a “training” code.

In yet another embodiment of the invention, the transmitter 126 may havemultiple unique codes and the transmitter randomly selects one of themultitude of possible codes, all of which are programmed into the memoryallocation spaces 147 of the microprocessor 244. Furthermore, thetransmitter 126 may have multiple selectable codes. As mentioned abovetwo or more codes may be selected using one or more membrane switches321, 322. In a system with more than one code and preferably 2-60 codesa separate selector switch 45 may be used, as shown in FIGS. 21-24. Aselector switch 45 is preferably mechanically connected to the input ofthe encoder 40. By changing the position of the selector 45, the inputto the encoder 40 is changed, thereby changing the output code of theencoder 40 to correspond to the position of the selector switch 45. Theselector 45 may comprise a multi-position relay, a slider switch or adial, such as is used in thermostats. In an exemplary operation, theselector 45 may be set to 75 degrees and the deflector 72 is thendepressed. The encoder 40 then modulates a code onto the RF generator 50corresponding to “CHANGE TEMPERATURE TO 75 DEGREES” which is receivedthe by the receiver module 101. The receiver module then changes theposition of the relay(s) at the heating/cooling appliance to change thetemperature to 75 degrees. As described further hereinbelow, thereceiver module 101 may transmit through a transceiver 450 a feedback orconfirmation signal indicating that the desired temperature has been setor achieved.

In yet another embodiment of the invention, the transmitter 126 signalneed not be manually operated or triggered, but may as easily beoperated by any manner of mechanical force, i.e., the movement of awindow, door, safe, foot sensor, etc. and that a burglar alarm sensormight simultaneously send a signal to the security system and a light inthe intruded upon room. Likewise, the transmitter 126 may be combinedwith other apparatus. For example, a transmitter 126 may be locatedwithin a garage door opener which can also turn on one or more lights inthe house, when the garage door opens.

Furthermore, the transmitters can talk to a central system or repeaterwhich re-transmits the signals by wire or wireless means to lights andappliances. In this manner, one can have one transmitter/receiver set,or many transmitters interacting with many different receivers, sometransmitters talking to one or more receivers and some receivers beingcontrolled by one or more transmitters, thus providing a broad system ofinteracting systems and wireless transmitters. Also, the transmittersand receivers may have the capacity of interfacing with wiredcommunications like SMARTHOME or BLUETOOTH, and ZIGBEE.

It is seen that the present invention allows a receiving system torespond to one of a plurality of transmitters which have differentunique codes which can be stored in the receiver during a program mode.Each time the “program mode switch” 222 is moved to the programposition, a different storage can be connected so that the newtransmitter code would be stored in that address. After all of theaddress storage capacity have been used additional codes would erase allold codes in the memory address storage before storing a new one.

This invention is safe because it eliminates the need for 120 VAC (220VAC in Europe) lines to be run to each switch in the house. Instead thehigher voltage overhead AC lines are only run to the appliances orlights, and they are actuated through the self-powered switching deviceand relay switch. The invention also saves on initial and renovationconstruction costs associated with cutting holes and running theelectrical lines to/through each switch and within the walls. Theinvention is particularly useful in historic structures undergoingpreservation, as the walls of the structure need not be destroyed andthen rebuilt. The invention is also useful in concrete construction,such as structures using concrete slab and/or stucco construction andeliminate the need to have wiring on the surface of the walls and floorsof these structures. Furthermore, remote transmitters may be fitted withhole and screws to mount over existing switch boxes in walls, or bemounted over the existing switch boxes, using adhesives, magneticmounting, screws, bolts, hook and loop, snaps, hooks, or otherfasteners.

Referring now to FIGS. 21 and 23-24: While in the preferred embodimentof the invention, the actuation means has been described as frommechanical to electric, it is within the scope of the invention toinclude a supplemental power source, such as batteries 430 in thetransmitter to power or supplement the power of the transmitter. Forexample, long life rechargeable batteries 430 may be included in thetransmitter circuitry and may be recharged through the electromechanicaltransducers 12. These rechargeable batteries 430 may thus provide backuppower to the transmitter 50. The circuits illustrated in the figures arethe same as those described herein above, with the exception of theaddition of rechargeable batteries 430 in the circuit. In the circuit ofFIGS. 21 and 23, the ground terminal of the battery is connected toground and the positive terminal is connected to the output side of therectifier before the voltage regulator. In the preferred circuit ofFIGS. 21 and 24, the ground terminal of the battery is connected toground and the positive terminal is connected to the output side of thevoltage regulator U2 before the transmitter subcircuit 50. Power may besupplemented to the transmitter/transceiver using other supplementalpowers sources 460 such as solar or light power, e.g., by photoelectriccells used in some calculators), by changes in temperature(thermoelectric), or by changes in pressure.

Referring now to FIGS. 21 and 24: The circuit of FIG. 21 includes arechargeable battery as in the circuit of FIG. 24. However, in thiscircuit, the output of the voltage regulator U2 is connected only to thepositive/charging terminal of the rechargeable battery 430, i.e., thevoltage regulator U2 output is not connected directly to the input sideof the transmitter subcircuit 50. The output of the rechargeable battery430 is connected to the input side of the transmitter subcircuit througha switch S1. The switch S1 may comprise a transistor. When the switch S1is closed/energized, electrical power is applied to the transmittersubcircuit. The switch may be energized when the deflection meansactivates the transducer 12. When the transducer 12 is deflected, anelectrical output is produced, most of which is rectified and regulated,and then used of charge the battery 30. A small amount of the electricalpower is tapped by a filter/trigger 420 from the transducer 12 (usingfor example a BJT connected between a grounded resistor and a secondresistor between the BJT and the transducer 12), which electrical energyis applied to the switching device in order to electrically connectedthe battery to the transmitter subcircuit.

Referring again to FIGS. 21 and 23-24: In another embodiment of aself-powered transmitter circuit, the rechargeable battery 430 orsupplemental power source 460 not only provides power for transmissionof a coded signal, but also provides power to a low power consumptionreceiver 450. In the preferred embodiment, the receiver/transmittercomprises a single transceiver 450. The transceiver 450 is electricallyconnected to the battery as in FIGS. 21 and 23-25. However, in additionto the transmitter/transceiver 450 transmitting in response to a triggersignal from the transducer 12 that energizes the switch S1, thetransceiver 450 will also transmit in response to the reception by thereceiver portion of the transceiver 450 reception of an RF signal.

In the preferred embodiment of the transceiver based circuit, when thetransceiver 450 receives a coded signal corresponding one or more codesstored in the transmitter PIC (i.e., a polling code, a verificationcode, an on/off code, a feedback code), then the transmitter portion ofthe transceiver 450 will transmit its coded RF signal. The transmitterRF code signal may correspond for example, to a transmission code of itscurrent state, for use as an error detection code or a verification codeor as a supplement to one or more of these codes. The code transmittedby the transceiver in response to a received code may be forwarded to acentral system such as a microprocessor that can display the status ofmultiple transceiver systems, for example in a security system.

The output of the transceiver may also be connected directly to adisplay 470 at the transceiver 450. The display 470 may comprise forexample a low power consumption display such as an LED or LCD displaycapable of showing alphanumeric characters and/or colors, such as greenfor “ON” and red or black for “OFF”. The display 470 for example mayshow the code or command function last transmitted by the transceiver450, as well as receipt of a confirmation signal from the transceiver270, 450 in the receiver module 101. This is useful for example in awireless thermostat systems, wherein the transmitter 126 transmits atemperature signal to a receiver 101, and the receiver module 101 sendsa confirmation signal to the transceiver indicating receipt of thesignal and or completion of setting the temperature to the levelindicated in the signal. The display is powered either through thebatteries 430 or the supplemental power source 460, and most preferablyby a solar/light power source 460. The battery supplemented transceivers450 are preferably made compatible with present low-cost, very low powerconsumption, two-way, digital wireless communications standards such asZIGBEE and BLUETOOTH. The transceivers and/or display may also besupplemented by not only batteries, but also the aforementionedphotoelectric, thermoelectric or pressure-induced electrical powersupplies.

While the above description contains many specificities, these shouldnot be construed as limitations on the scope of the invention, butrather as an exemplification of one preferred embodiment thereof. Manyother variations are possible, for example:

In addition to piezoelectric devices, the electroactive elements maycomprise magnetostrictive or ferroelectric devices;

Rather than being arcuate in shape, the transducer 12 may normally beflat and still be deformable;

Multiple high deformation piezoelectric transducers may be placed,stacked and/or bonded on top of each other, as well as transducershaving multiple layers on a single substrate;

Multiple piezoelectric transducers may be placed adjacent each other toform an array;

Larger, multilayer and different shapes of THUNDER elements may also beused to generate higher impulses;

The piezoelectric elements may be flextensional transducers; direct modepiezoelectric transducers, and indirect mode piezoelectric transducers;

A bearing material may be disposed between the transducers and therecesses or switch plate in order to reduce friction and wearing of oneelement against the next or against the frame member of the switchplate;

Other means for applying pressure to the transducer may be usedincluding simple application of manual pressure, rollers, pressureplates, toggles, hinges, knobs, sliders, twisting mechanisms, releaselatches, spring loaded devices, foot pedals, game consoles, trafficactivation and seat activated devices.

1. A self-powered switching system, comprising: an electroactivetransducer having first and second ends, said electroactive transducercomprising; a first electroactive member having opposing first andsecond electroded major faces and first and second ends; a flexiblesubstrate bonded to said second major face of said first electroactivemember; said flexible substrate having first and second ends adjacentsaid first and second ends of said first electroactive member; whereinsaid electroactive transducer is adapted to deform from a first positionto a second position upon application of a force to said electroactivetransducer; and wherein said electroactive transducer is adapted toreturn to said first position from said second position upon release ofsaid force from said electroactive transducer; and wherein upon saiddeformation from said first position to second position, saidelectroactive transducer is adapted to generate a first voltagepotential between said first electroded major face and said secondelectroded major face; and wherein upon said return from said firstposition to second position, said electroactive transducer is adapted togenerate a second voltage potential between said first electroded majorface and said second electroded major face; a mounting member forretaining said first end, said second end or said first and second endsof said electroactive transducer; said mounting member comprising atleast one retaining means adjacent said first end, said second end orsaid first and second ends of said flexible substrate of said firstelectroactive member; mechanical deflection means for application of aforce to said electroactive transducer, said mechanical deflection meansbeing adapted to apply a force sufficient to deform said electroactivetransducer from said first position to said second position, therebygenerating a first voltage potential; a first conductor electricallyconnected to said first electroded major face of said firstelectroactive member; a second conductor electrically connected to saidsecond electroded major face of said first electroactive member; arectifier having an input side and an output side; said input side ofsaid rectifier being electrically connected between said first andsecond conductors in parallel with said first and second electrodedmajor faces of said electroactive transducer; a voltage regulator havingan input side and an output side; said input side of said voltageregulator being electrically connected to said output side of saidrectifier; an encoder having an input and an output side, said outputside of said voltage regulator being connected to said input side ofsaid encoder; said encoder being adapted to generate a coded waveform;an output signal at said output side of said encoder being an electricalsignal having said coded waveform; first signal transmission meanselectrically connected to said output side of said encoder; said firstsignal transmission means comprising a first radio frequency generatorsubcircuit connected to an antenna; said radio-frequency generatorsubcircuit being adapted to generate a first radio-frequency signalmodulated by said output signal of said encoder for transmission by saidantenna; signal reception means for receiving a first signal transmittedby said first signal transmission means; said signal reception meansbeing adapted to generate a relay signal in response to said firstsignal transmitted by said first signal transmission means; and a relaydevice for operating an electrical appliance; said relay device being incommunication with said signal reception means; said relay device havinga plurality of positions, each of said positions in said plurality ofpositions corresponding to an operating mode of said electricalappliance said relay device being adapted to change between a firstposition to a second position in said plurality of positions in responseto said relay signal.